Among pulses, pea is an important legume crop which is not only the major source of proteins but also provide significant amount of carbohydrates, minerals and vitamin B complex. The current research work was planned to study genetic diversity among available pea germplasm and to evaluate inheritance pattern controlling seed yield related traits in Pisum sativum L. For this purpose 99 pea genotypes were field evaluated following RCBD replicated thrice. Data were taken for seed yield and its related traits. All the studied parameters showed significant amount of variation among genotypes. The cluster analysis classified 99 pea accessions into three clusters on the basis of genetic diversity of seed yield and its related traits. Eight accessions namely 19605, 20202, 26710, 20300, 19716, 20126, 26701 and 20153 were selected from cluster I and III for hybridization. Selected genotypes were crossed in 8×8 half diallel fashion excluding reciprocals to study the inheritance patterns for yield and quality traits. Twenty eight F1 crosses and parents were field evaluated during winter season 2015-2016 while F2 of all crosses was evaluated during winter season 2016-2017. Analysis of variance displayed significant amount of variation for all the studied parameters in both generations. The accession 20126 was good general combiner for number of branches per plant, biological yield, carotenoids contents and seed yield per plant in F1 generation while the accession 20153 was good general combiner for pod length, hundred fresh seed weight, hundred dry seed weight, harvest index and seed yield per plant in F2 generation. The cross combination 20202 × 26710 was good combination for pod length, pod width and seed yield per plant in F1 generation while the cross combination 19605 × 20202 was found best combination for seed yield per plant in F2 generation due to maximum significant and positive specific combining ability effects for seed yield per plant. The cross combination 20202 × 26710 showed maximum mid parent as well as better parent heterotic effects for pod length and seed yield per plant in F1 generation. The correlation analysis in F2 generation showed that number of branches per plant, pod length, biological yield and harvest index was significantly and positively correlated with seed yield per plant in Pisum sativum L. The cross combination 20202 × 26710 may be used as hybrid due to its higher specific combining ability variance and heterotic effects for seed yield per plant. Presence of non additive effects advocated the importance of heterosis breeding for development of high yielding varieties in pea.