The genus Ischnocolus is redefined based on type material, and extra specimens. Representatives of the genus are distinguished by clavate tarsal trichobothria arranged in median apical row; by the maxillae with lighter colour on prolateral edge. Males of the genus Ischnocolus Ausserer are recognized by the cheliceral intumescence, sigmoid ventral furrow on palpal tibia, unequal cymbium lobes, tibial apophysis absent, great number of spines on ventral side of tibia I, and male superior tarsal claws bipectinate. Species included are: Ischnocolus valentinus (Dufour) [= I. holosericeus L. Koch, I. triangulifer Ausserer, I. algericus Thorell, I. fuscostriatus Simon, I. maroccanus (Simon), I. mogadorensis (Simon), I. numidus Simon, I. tripolitanus Caporiacco, Avicularia andalusiaca Simon], Ischnocolus hancocki Smith, Ischnocolus jickelii L. Koch (senior-synonym of Chaetopelma adenense Simon) and Ischnocolus ignoratus sp. nov. Ischnocolus tomentosus Thorell is considered incertae sedis. The following species are considered species inquirenda: I. tunetanus Pavesi and I. fasciculatus Strand.