Hamilton police responded to call about a possible impaired driver in the area of Centennial Parkway and South Service Road.
It happened Wednesday night around 8:00 p.m. after a small black pick-up truck was seen driving erratically.
When police stopped the truck, they found the occupants were in possession of fentanyl.
Two men, ages 62 and 44, and a 36-year old woman, all from St. Catharines, are charged with possession of a controlled substance and failing to comply with probation
The three were released with future court dates.