The species of Glaucium have been used in traditional medicine in Turkey as hypnotic, sedative and in the treatment of cough (1). In this study, the isolation of the alkaloids from Glaucium Ieiocarpum Boiss. (Papaveraceae) is described. Previous investigations on the alkaloids of this species revealed the existence of glaucine, dehydroglaucine, oxoglaucine, auratensine, isocorydine, corydine, protopine, chelerythrine, chelidonine, sanguinarine and dihydrosanguinarine (2).In the present study the main alkaloid of the aerial parts of G. leiocarpum Boiss. was (+)-glaucine (1). 6,6a-Dehydronorglaucine (2), oxoglaucine (3), (+)-N-methylglaucine (4), (+) lastourvilline (5), (+)-predicentrine (6), (+)-dihydropontevedrine (7) (aporphine), secoglaucine (8) (phenanthrene), (—)- N-methylcoclaurine (9) (benzyltetrahydroisoquinoline), protopine (10), allocryptopine (11) (protopine) were isolated as minor alkaloids. The presence of 2, 4—9, 11 has been shown for the first time in G. leiocarpum. This is the first report of the isolation of 4 from the genus Glaucium and of 5 and 8 from Papaveraceae.