Background: Considering global warming and climate changes, grass pea (Lathyrus sativus L.) is becoming advantageous and popular with its characteristics such as resistance to biotic stresses. The objective of the present study was to determine the variations in fatty acid and organic acid content in induced grass pea populations. Methods: Forty-one grass pea genotypes that include forty mutant genotypes and one released variety (Gürbüz-2001) were investigated in term of fatty acids using the GC-MS device and organic acids using UPLC-MS/MS device. Result: Heptadecanoic acid, stearic acid, oleic acid, linoleic acid and α-linolenic acid were determined as major fatty acid constituent in forty mutant genotypes. In saturated fatty acids, the highest values were determined as 403.24, 401.39 and 398.87 mg 100 g-1 (in GPM5, GPM20, GPM34), respectively. Compared the control cultivar, the maximum values of GPM21 (18.77%), GPM5 (18.68%) and GPM33 (18.12%) were higher in PUFA. And in the similar, the values of GPM19 (11.52%), GPM28 (10.54%) and GPM4 (5.62%) were lower obtained in PUFA. As the maximum values of succinic, lactic, oxalic, citric and tartaric acid were obtained in GPM9, GPM37 and GPM11, the lowest values were found in GPM4, GPM13 and GPM18, respectively. The values of fatty acids and organic acids, important criteria for animal feeding and human nutrition, will guide further breeding studies for the development of these 40 mutant genotypes.