<p>The foremost drawback of lablab bean (<i>Lablab purpureus</i> L.) improvement is the narrow genetic base for traits of interest available in the germplasm. Study of combining ability helps in selection of suitable breeding methods and parents for crossing to develop a variety. A field experiment with lablab bean was conducted with the objective of determining combining ability and heterosis for yield and yield related characters using 5 × 5 half diallel populations. Analysis of variance for parents and F₁s indicated significance for all characters except edible pod width and parental vs. F₁s for all characters except edible pod length and edible pod width. General combining ability (GCA) variance was significant for all characters except edible pod width. The specific combining ability (SCA) variance was significant for most characters except number of pods per inflorescence, edible pod length, edible pod width and edible pod weight. There was a combined role for additive and non-additive gene actions. The ratio of GCA to SCA variance was higher than unity for all characters indicating preponderance of additive gene actions over non-additive gene action played a role in inheritance of these characters. Estimates of GCA effects were significant, and negative, parents Seem 1 (P1) and Seem 2 (P2) indicating they are good general combiners for early flowering, edible pod maturity and early seed maturity. Parents P1 (Seem 1) and P2 (Seem 2) were good general combiners for higher pod yield per plant. The estimates of SCA effects exhibited significant, positive, values for pod yield per plant in the cross combinations Seem 1 × Seem 2 (9.20**), Seem 1× CB 086 (2.51**) and CB 021× CB 086 (4.34**) could be used as the best combiners for improving pod yield. The hybrids Seem 1× Seem 2 and Seem 2× CB 021 were the best performers for pod yield per plant and earliness, respectively, for mid- and better parent heterosis. The cross combinations having high SCA could not be exploited as commercial hybrid because of highly self-pollinated nature of lablab bean. The cross involving the parent with high GCA for yield related traits could produce desirable transgressive segregants in the subsequent generations which could be utilized for improvement in yield in lablab bean.</p>