Plant breeding researches is based on genetic diversity and evaluation of genetic diversity is also one of the most important steps in introduction of new cultivars. In this study, genetic diversity of 25 grass pea genotypes was studied based on randomized complete block design with three replicates in Khorramabad (Iran). Analysis of variance showed significant differences among genotypes for most of traits. Mean comparison showed that genotype IF1312 with the highest grain yield and genotypes IF1332 and IF471 with the highest dry and fresh forage yield had the best yield. Principal component analysis showed that the first 3 factors explained 62.64% of total variance. Based on cluster analysis, genotypes IF1307, IF1872 and IF471 with the highest grain and forage yield are belonged to one cluster. REML method was used to estimate genetic correlation and heritability of different traits. The highest amount of heritability (0.87) was estimated for number of immature grains and the least heritability (0.10) was estimated for total dry weight. Grain yield had a high and positive genetic correlation with forage yield, and biomass, percentage of leaf and dry forage yield also had a high and positive genetic correlation with fresh forage yield. Totally, genotype IF1307 had the best performance for most of traits compared to the other genotypes and had an acceptable forage yield among genotypes.