An endochitinase gene (chit33-cDNA) from the biocontrol fungus Trichoderma atroviride was overexpressed under the CaMV35S constitutive promoter in canola (R line Hyola 308). Transformation of cotyledonary petioles was achieved via Agrobacterium tumefaciens. The insertion of the transgene was verified by PCR and Southern blotting. The transgenic over-expression approach was used in order to investigate antifungal activity of expressed Chit33 on Sclerotinia sclerotiorum. Antifungal activity was detected in transgenic canola using detached leaf assay. Lesion sizes of transgenic canola caused by S. sclerotiorum were significantly retarded when compared to non-transgenic canola plant.