Randall, K. M., Reaney, M. J. T. and Drew, M. D. 2013. Effect of dietary coriander oil and vegetable oil sources on fillet fatty acid composition of rainbow trout. Can. J. Anim. Sci. 93: 345-352. A 16-wk feeding trial was conducted to examine the effect of adding coriander oil to vegetable oil (VO) diets on the bioconversion of linoleic acid (LA; 18:2n-6) to arachidonic acid (ARA; 20:4n-6) and alpha-linolenic acid (ALA; 18:3n-3) to eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) in rainbow trout. The experimental treatments were a 4×2 factorial arrangement of diets using four dietary oils (fish, flax, canola and camelina oils) and two levels of coriander oil (0 and 5 g kg^-1 inclusion levels). Twenty-four tanks of triploid female rainbow trout (130 g initial weight; n=3) were used in the experiment. The experiment lasted 112 d during which fish were fed to satiation twice per day. The fatty acid composition of fillets from coriander-fed fish had increased concentrations of 20:5n-3 and 22:6n-3 (P<0.05). Furthermore, a trend to increased (20:5n-3 22:6n-3)/20:4n-6 ratios was seen when coriander oil was added to the diet (P=0.067). These results suggest that the addition of coriander oil to VO diets can significantly increase the bioconversion of 18:3n-3 to 20:5n-3 and 22:6n-3 in rainbow trout.