Keith McCardle,51, consumed four alcoholic drinks before getting behind the wheel of his Land Rover Freelander jeep on December 8 2012.
The High Court in Edinburgh heard how he lost control of the vehicle in the city's Dundas Street and his vehicle mounted the pavement there. He was more than one and a half times over the legal drink driving limit.
His vehicle struck dad-of-two Gavin Fulton,43, who was heading to his home in Edinburgh's Claremont Bank. Moments after the collision, McCardle got out of his car and told a passer-by: "I killed him. I hit the guy and he's dead."
On Friday, judge Lord Doherty told McCardle that he had no option but to send him to prison - he was also banned from driving for eight years.
Lord Doherty added: "Your dangerous driving ended Mr Fulton's life. It has caused inestimable damage to the lives of his family and others. No sentence that I can impose can undo that damage."
McCardle, of Musselburgh, East Lothian, pleaded guilty to causing Mr Fulton's death by dangerous driving at a hearing last month. Sentence had been deferred in order for the court to obtain reports about his character.
On that occasion Leanne Cross told the court that McCardle had four alcoholic drinks on a night out in Edinburgh's Bennets Bar.
At about 1am, he left the pub and started driving to Dundas Street.
Ms Cross added: "As the accused drove down Dundas Street, the witnesses travelling behind him saw the Freelander zig zag and swerve across the road in an erratic manner and out of control.
"The Freelander crossed from the carriageway it was on into the opposite carriage way and then mounted the pavement on the opposite side of the road between parked cars.
"As it mounted the pavement the Freelander hit the post on the pavement before striking the deceased on the pavement."
The court heard that medics rushed Mr Fulton to Edinburgh's Royal Infirmary Hospital. When he arrived Ms Cross told the court that doctors pronounced him dead at 6.40am. McCardle was then arrested.
On Friday, defence advocate Tony Lenehan said his client was genuinely remorseful for getting behind the wheel of his car drunk.
Mr Lenehan also said that his client had started drinking heavily when his brother David died after being assaulted by Ryan Cameron,26, in the Clubhouse Bar in Musselburgh two years ago.
Cameron, of East Lothian, was jailed for four years at the High Court in Glasgow in November 2012 for killing Mr McCardle by striking him with a metal beer keg.
On Friday Mr Lenehan said: "It was against that background that drink became a crutch to Mr McCardle. Mr McCardle's marriage had also came to an end.
"He had become distant from his family and friends and had withdrawn from social occasions. However, he felt he had addressed that issue.
"On the night in question he felt sober and he judged it safe to drive home.
"He knows there is no sentence that can reduce the grief and suffering of the deceased's family and friends.
"The consequences of his actions will live with him forever."
However, Lord Doherty said he had no other option but to send him to jail.
He added: "As has been said by a very senior judge 'Everyone knows or should know that the consumption of small quantities of alcohol undermines the ability of any driver to apply his full concentration to the road'.
"In my opinion your culpability is substantial because you decided to take the risk of driving when you knew you had consumed the quantities of alcohol which you had.
"I have listened to all that has been said on your behalf. Prior to this offence you had a good work record and you had only three previous convictions.
"I am in doubt however that the gravity of the offence requires that I impose a substantial prison sentence."