Hillhead Primary School, in Glasgow's west end, was given a "very good" grading on all aspects of its performance, including the experience of pupils, the curriculum and self-improvement.
Hillhead, now the city's largest primary school, was opened in 2011 after the merger of the former Hillhead, Dowanhill, Kelvinhaugh and Willowbank primaries as well as two nurseries.
The plans were controversial because parents did not want to lose their former schools and feared the new primary was too large, with a capacity of 666 pupils and 60 full-time nursery places.
In addition, there were concerns over whether the site for the new school, next to Kelvingrove Park, was large enough to accommodate so many pupils, as well as fears over road safety.
However, an inspection report by Education Scotland, published yesterday, praised the way the school's senior management team, led by headteacher Francis Donaghy, had managed the change.
The report stated: "The headteacher provides highly effective leadership and offers a clear vision to ensure that every child develops as a vibrant and successful learner. He has led the very successful amalgamation of four schools, including the original Hillhead Primary.
"He is very well respected by parents, staff and pupils. The school has benefited greatly from this high-quality leadership in what has been a challenging two years of change."
The inspection report said pupils were "very well behaved, friendly and articulate" and highlighted the "international and rich culturally diverse community" of the school.
"Children are making very good progress in literacy and good progress in numeracy," the report added. "Children show a keen interest in reading and can discuss enthusiastically the novels they have read. Writing across the school is of a very high standard."
Mr Donaghy said: "Parents and staff have worked very hard to create a new community here and it was very rewarding to hear from the inspectors that, after just two years, they could not tell which schools pupils had originally come from."
Inspectors also praised the performance of another large primary school - Mearns Primary in Newton Mearns, East Renfrewshire, which has more than 800 pupils.
Seven of the eight areas evaluated were considered "excellent", including the curriculum and improvements in performance.
Inspectors praised the "outstanding" quality of children's learning and achievement and the "inspirational" leadership of headteacher Ann Macbeth, who has since retired after nine years leading the school.
The report said children enjoyed school, had very positive attitudes to learning, were enthusiastic and offered "thoughtful opinions and ideas" in lessons.
Elaine Green, the council's education convener, said: "Congratulations to all of the staff and pupils for a truly excellent report.
"It is wonderful to read that the inspectors consider the quality of learning and achievement as outstanding, that children are making very strong progress in their learning and that the staff are supporting the pupils to learn so effectively."