Barry comprehensive, in the Vale of Glamorgan, has already featured twice in the Welsh qualifications, curriculum and assessment authority's (ACCAC's) annual awards.
It was a regional winner in 2002 and won the national title for most improved school in 2003. The school improvement index award-winners for 2004 will be announced on Monday.
Inspection agency Estyn's recent annual report highlighted a continuing and, in some subjects, widening performance gap between boys and girls.
But Barry headteacher David Swallow says: "The gender gap doesn't exist here."
Last year the percentage of pupils achieving five or more A* to C grades at GCSE rose from 53 to 70 per cent, beating the local girls' school. But just five years ago, Barry boys had a reputation for toughness and poor achievement. In 1999, only 24 per cent of pupils were reaching the benchmark.
What's the magic answer? "There are a number of strands, and one is having a curriculum that meets the needs of the pupils in this school," says Mr Swallow.
In Barry's case, that has meant the introduction of vocational courses in information and communications technology, performing arts, hospitality and catering, engineering and manufacturing - all worth multiple GCSEs.
"Three years ago we had a group of lads in Year 10 we felt were unlikely to see out the end of Y11, through disaffection and poor attendance. They were the worst 20 in the year group, both academically and behaviourally," says Mr Swallow.
Working with a local college, the boys were offered a GNVQ course in hospitality and catering, worth four GCSEs. Despite the extra hours required in school and college, the group flourished. And much of that was to do with being offered the opportunity to succeed in bite-sized chunks, says Mr Swallow.
"We all need success. Very often these boys had been told what they couldn't do. Rarely had they been told what they could do."
Sixteen of the group got the full award, and of those 12 got other GCSEs.
Mr Swallow has no doubt that success in one area helped to motivate them in others, and this is the reason he dismisses claims that GNVQs are an easy way of boosting headline results.
In England last year, six of the 10 top-performing secondaries told The TES that the rise in their results would have been significantly lower if they had not introduced GNVQs. The courses are due to be phased out by 2007.
John Williams, chief executive of ACCAC, said its index of improvement looked at schools' results over six years.
"You can't do an easy fix now to improve results next year," he said.
"Schools should be innovative in the way they deliver the curriculum, and we applaud that."
For Barry's Y11 pupils, the benefits of a broader curriculum are apparent.
Lewis Stait is confident that the extra work he is putting in for his ICT qualification is going to "open more doors". And Sean Morrison says pupils are now "more trusted by the teachers - we're treated like adults".