Ethiopian mustard (Brassica carinata A. Braun) is a highly productive oilseed crop in the central highlands of Ethiopia. Cultivars currently in production in Ethiopia produce seed which contains 35-40% erucic acid in its oil which is undesirable for human consumption. Zero erucic acid B. carinata has recently been developed. The objective of this study was to investigate the inheritance of erucic acid in progeny of crosses between the high erucic acid cultivars Dodolla and S-67 with the zero erucic acid line C90-14. The erucic acid content of F-1 seed born on either the high or low erucic acid parents was intermediate between the parents indicating embryonic control of erucic acid content in B. carinata. Erucic acid contents of backcross seed derived from the backcross to the zero erucic acid parent segregated into three classes with <0.5%, 6-16% and >16% erucic acid at a ratio of 1:2:1 and F(2)seed segregated into five classes with a ratio of 1:4:6:4:1. These segregation patterns indicated that erucic acid in B. carinata was controlled by two genes acting in an additive manner with each locus contributing about 10% erucic acid. It was concluded that the B and C genomes of B. carinata each carry one gene for erucic acid synthesis. The knowledge of the inheritance of erucic acid in B, carinata will assist in the development of zero erucic acid B. carinata cultivars.