A set of 10 x 10 Diallel crosses excluding reciprocals and parents were evaluated in two years for seed yield and it important yield component traits including oil content in Indian mustard (Brasica juncea IL) Czern and Cossl. Results revealed the importance of additive and non-additive genetic variances for most of the characters studied. However, only additive genetic variances made significant contribution in inheritance seeds/siliqua in both years and for plant height and oil content in second year. Widely adapted mustard variety Kranti and promising line PHR-2 were identified as best general combiners for most of characters studied followed by Pusa bold, Pusa barani and RLM-198. Early maturing dwarf strain Divya was identified as best general combiner for early flowering and maturing and dwarf height. Results revealed that the crosses with the highest mean did not possess the highest sea effects. Divya x Zem-l, Kranti x EC-322090, RLM-198 x EC-322090, EC-322090 x EC-322092, Divya x EC-322090.and Pusa barani x Divya showed high sea effects for yield and its component characters. Desirable transgressive segregants for various characters are expected from these crosses.