In his wildest dreams, Haile Gebrselassie never imagined the race he founded 11 years ago would become Africa's largest mass-participation running event.

The man known as the Little Emperor fired the starter's pistol for the 2001 Great Ethiopian Run, then jumped into the fray to become the first winner. There were 10,000 runners registered that day, along with thousands more "bandits", who didn't sign up.

Driven by his enthusiasm, the 2012 edition set off last month from Addis Ababa's Meskel Square with more than 36,500 eager participants. Gebrselassie could hardly contain his pride.

"What I expected was a normal race, a race that is organised by the Ethiopians, nothing else," he says of the prestigious 10-kilometre event that winds through the hilly streets of the Ethiopian capital. "We started small and thanks go especially to Newcastle's Great North Run organisers. They helped this event. I am really happy now. We are very close to the big international events like the London Marathon and the New York Marathon."

Gebrselassie befriended Brendan Foster whose company, Nova International, organises the Great Run series across the UK. Along with former British international marathoner Richard Nerurkar and a local organising committee, they helped launch the annual event a year after Gebrselassie won his second Olympic 10,000m gold medal in Sydney.

The race, with its carnival atmosphere, has become one of the country's biggest spectacles. Gebrselassie is everywhere – speaking at a press conference, posing for pictures at the international pasta dinner on the eve of the race and always available to fulfil the numerous interview requests.

On the day preceding the main event, more than 3500 children, aged three to 11, contested distances from 500 metres to 1500 metres at the Jan Meda race track, the site of Ethiopia's national cross-country championships. Backed by Plan International's "Because I am a Girl", an organisation which seeks to empower girls, the races are an opportunity to sow the seeds for future generations. The kids warmed up by dancing to Ethiopian music blaring from the stage in the middle of the field. Gebrselassie served as the official starter.

Race day itself begins as the sun rises with thousands warming up on the steps of Meskel Square. The 500 elite runners are nowhere to be seen, however. They are given a 10-minute head start at a point around the corner, out of sight of the masses. In previous years their presence at the start had caused a safety concern with thousands wanting to sprint ahead of their heroes.

Gebrselassie says the race has launched the international careers of nearly all the country's Olympic champions.

"This is a very good opportunity for those who don't have races outside Ethiopia," he says. "This is an international race. Just by participating in the GER they have a chance to race outside Ethiopia. Many of our past participants have become world champions, Olympic champions, world record holders. Every year you never know who is going to win. Sometimes it is an unknown athlete. Like last year nobody expected Musnet Geremew to win and now he is an international athlete."

This year's event was no less competitive, with the 2012 Berlin Marathon champion, Aberu Kebede, winning the women's race in a time of 33:27, while world junior 5000m record holder Hagos Gebrhiwet won the men's race, equalling the course record of 28:37. The times reflect the difficulty of the course. Addis lies at 7500 feet (2300m) elevation and despite Gebrselassie's encouraging words at the pre-event press conference that "the course is not difficult, we have taken out two large hills", the race is not designed to elicit superfast times. The weather conditions – 24˚ celsius with no clouds – also exacts a toll. Perhaps for this reason Gebrselassie's advice to foreign runners was to stay behind the Ethiopians.

Winning the Great Ethiopian Run is one of the more prestigious accomplishments for an Ethiopian athlete. Kebede said as much when she was mobbed by the national press corps after her victory.

"Of course I am very proud as this is an important race for me," she said. "The course was tough and the competitors were strong. The weather was also a challenge. In the last kilometre I was scared to lose. I am used to running longer distances. I came here after the Berlin Marathon so this is a short race for me."

Long after the winners received their awards from Gebrselassie, naturally, runners, wearing identical green and red t-shirts, were still crossing the finish line. Many had stopped en route for drinks at the numerous bars along the course. Some had mingled with spectators too. The road was littered with empty water bags at the many refreshment stations.

The international component is limited to large numbers of charity groups. After all, which international elite runners want to tackle the Ethiopians on their home soil? Irish Olympic medallist John Treacy's "Concern", a worldwide humanitarian charity, is one prominent group. The 2012 race raised $72,000 to combat child poverty, adding to the $170,000 raised from 2005 to 2011.

Scottish representation included 21-year-old Rob Simpson of Aberdeenshire whose victory at the Balmoral 15km trail race earned him a trip to Addis. Admitting he was extremely nervous in the days leading up to the race, the Scottish Rural University College student thoroughly enjoyed the experience.

"There were 36,000 people running and so many of them are really good," he said with a huge grin after finishing in the middle of the field. "The people on the course were amazing, shouting the name of the country and cheering you on.

"Even the runners were really good. When there's a headwind they are telling you to tuck in behind them. They would run with you and pull you along. They would run in a friendly way rather than just trying to beat you. It was really good."

Simpson was among the 50 or so international guests invited back to Gebrselassie's home for a post-race luncheon. The lasting impression will likely ensure a larger overseas contingent signs on for the 2013 edition. But nobody will expect to beat the Ethiopians.