At the time of the decision, Warrington had about 200 students taking A-levels.
"It was a bit scary," said principal Paul Hafren. "We thought that we might take a financial hit but our numbers went up as a result."
Nobody was forced to move mid-course. All students were allowed to complete their A-levels at Warrington.
Learners seeking to study A-levels now choose between nine secondary schools with sixth forms and a sixth form college. Warrington previously saw itself as second or third choice for students following an academic route but now believes it is first choice for vocational studies.
Mr Hafren said: "It was better for us, and for our prospective students, that we majored in the things that we were good at. Our strengths are in vocational education and training."
In spite of Warrington's move, Mr Hafren does not believe most colleges will drop A-levels. He said: "Colleges have to strike a balance between their own strategy and future and how they serve the local population. The sector is a mixed economy."