A study of 8 Israeli population groups for the ORM1 polymorphism included 1242 serum samples: 156 samples from Arab Moslems, 139 from Arab Druzes, and 947 from 6 Jewish groups. The two most frequent alleles in Europeans and Asians, ORM1*F1 (ORM1*1) and ORM1*S (ORM1*2) were found in Jews and Arabs at frequencies similar to those in Europe. Unique to Arab and Jewish populations were polymorphic frequencies of two ORM1 slow electrophoretic variants, designated ORM1*S1 and ORM1*S2. These were formerly observed only in Europe, where two individuals with *S1 and two with *S2 have been observed so far. The Chueta community of converted Majorcan Jews is the only previously studied group that, like the other studied Jewish groups, has polymorphic frequencies of both ORM1*S1 and ORM1*S2. In this study we associate the Chuetas with the Israeli groups, as a population of Middle Eastern origin. Published data on ORM1 in Europe and East Asia together with the present data, making a total of 47 populations, were subjected to a discriminant analysis that resulted in a correct classification of 93.6% of the populations. Results of this analysis suggest that ORM1 is a useful polymorphic marker for anthropological studies.