Fifty-two grass pea (Lathyrus sativus L.) genotypes were investigated in terms of agronomic performance, protein and ODAP (b-N-oxalyl-1-diamino-propionic acid) content under semi-arid conditions of Inner Anatolia during 2013 and 2014. High variation was observed among genotypes, especially for seed yield and ODAP content. Seed yield ranged from 1142.4 kg/haup to 2046.4 kg/ha with a mean of 1521.1 kg/ha, ODAP content in seed varied from 2.62 mg/g up to 5.59 mg/g with an average of 3.85 mg per g and seed protein ratio was between 26.77% and 30.20% over the genotypes and years. A significant and negative correlation of ODAP was noted with seed yield (r = -0.38). This association is very encouraging for breeders to improve new varieties having high seed yield and low ODAP content. The results from this study indicated that ten grass pea genotypes consisting two ICARDA lines and eight landraces from Turkey recorded superior with low ODAP content and and high seed yield (changed between 1680.9 kg/ha and 2046.4 kg/ha). So, these may be potential candidates for new varieties.