Thirty-two samples of rapeseed consisting of eight cultivars (four Brassica napus and four Brassica campestris) grown at four different locations in Western Canada were used to study the effect of cultivar and growing location on the sinapine content of the seed. The results indicated that across location, the B. napus were significantly higher (P < 0.01) in sinapine than the B. campestris cultivars and the R-500 seed was lowest in sinapine content while the Midas seed was highest. While growing location had significant effects on the sinapine content of individual cultivars, no overall significant location effect was observed. The findings suggest that it might be possible, by selection, to develop varieties of rapeseed that are low in sinapine.