Four populations of Anopheles sacharovi Favre occurring in different ecological subregions at altitudes between 353-1,126 in in the Sanliurfa Province of southeast Turkey were compared using morphometric and allozyme analyses. Four allozyme loci were assessed for genetic differentiation among samples from four localities. The similarity phenogram obtained from the allozyme data showed that populations at Birecik and Sandi branched as a separate group from the Pamuklu and Gedik populations. The Gedik population at the highest altitude (1, 126 m) was clustered as a separate branch when linear measurements of 63 morphological characteristics were examined. The UPGMA phenogram. also showed that Pamuklu and Sandi formed a cluster while Birecik and Gedik formed separate groups.