YALE College chemistry students came first in the North Wales Area Schools Analyst Competition, organised by the Royal Society of Chemistry, at UCW (Bangor).
They were presented with their award last Friday.
Dr Maher Kalaji from the University of Bangor presented the awards on behalf of the Royal Society of Chemistry.
Yale's winning students were Sara Mahmoud, of Overton, Lewys Jones, of Treuddyn, near Mold, and Stephen Wilson, of Cefn Mawr.
All three students are studying the sciences at AS level at Yale with the intention of progressing to a full A-level in chemistry next year.
Many schools from North Wales took part in the competition, which involved a practical investigation into the use of aluminium sulphate in the water treatment industry.
As a reward for achieving first place, the students will each receive an engraved glass miniature rose bowl and the college will gain a computer system.
And as a further reward for their success, the students will each receive a cheque to the value of £50 from the college.
The team of three students will go forward to represent the area in the national final at the University of Liverpool later in the year.