A complete diallele crosses derived from eight oilseed rape (Brassica napus L.) genotypes was used to estimate the genetic parameters for seed yield, 2-propenyl (allyl), 3-butenyl, total glucosinolate, oil and protein contents. Analysis of variance based on Griffing's Method one with Mixed- B Model revealed the presence of significant mean squares for general and specific combining abilities and reciprocal effects, indicating additive, non-additive and maternal effects, contributed to genetic control of the studied characters. High narrow-sense heritability estimates for the three types of glucosinolates indicated the prime importance of additive genetic effects. However, the degree of dominance greater than one for seed yield, oil and protein contents showed the importance of non-additive genetic effects for these traits. Significant heterosis over better parent was detected for allyl, 3-butenyl and total glucosinolate contents, seed yield, oil and protein percentages. Non-significant correlation between studied traits and seed yield suggested the possibility of improving these traits without any considerable changes in the seed yield. In general, PF7045/9 I and BL I (breeding lines) were good combiner parental lines for seed yield and low glucosinolates. The crosses PF7045/91 x Shiralee and BL1 x PF7045/9 I had the highest positive and negative heterosis for seed yield and glucosinolates, respectively.