AROUND 40 per cent more students gained the benchmark GCSE results in the city and county last year than in 2008, Department of Education figures have revealed.
Of students who sat last year's exams in county schools, 60.6 per cent gained at least five A* to C grades including English and maths.
This was up from 43.3 per cent four years earlier.
Meanwhile, the city saw a rise from 34.7 per cent in 2008 to 49.6 per cent last year.
The rise in the county has been put down to the worst-performing schools being matched up with stronger schools.
Councillor Philip Owen, Notts County Council committee chairman for children and young people's services, has challenged schools to improve further.
He said: "Whilst these results are exceptionally good, we need to look forward now. I believe Nottinghamshire schools can achieve even greater things in the immediate future.
"If the rate of progress continues at this pace, over the next two years I'd like to see 70 per cent of our pupils achieving five or more A* to C grades."
The county figure was above the national average of 59.4 per cent, placing it 56th out of the 151 local education authorities.
The top-performing school in the county was Orchard School in Retford, where 96 per cent of its 25 students gained at least five A* to C grades with English and maths.
The next best was West Bridgford, with 88 per cent of 221 students, followed by Minster School in Southwell, with 85 per cent of 237 students reaching the benchmark.
Some schools which had previously struggled saw significant rises in performance, such as Meden School in Mansfield, where the proportion reaching the benchmark rose from 53 per cent to 67 per cent.
The school is overseen by Torch Academy Gateway Trust, which also sponsors Toot Hill in Bingham.
John Tomasevic, head at the trust, said: "It's been a terrific rise from the situation the school was in. We have made significant changes."
In spite of the improvements in the city, more than half of students didn't reach the expected grades.
Councillor David Mellen, portfolio holder for children's services, said: "We have seen a big rise in recent years. Hopefully we can continue to do so. The council works with the schools and has a good partnership with those which have become academies."