Review of world genus-group taxa heretofore assigned to Tychiinae indicates that the subfamily should be delimited to include the genera Apeltarius Desbrochers, Dichotychius Bedel, Itychus Kissinger, Mecynopyga Pierce, Paragoges LeConte, Sibinia Germar, Tychius Germar, Xenotychius Reitter, and their subgenera and synonyms. The status and relationships of formally recognized genus-group taxa within the genus Tychius are reviewed. Henonia Pic and Miccotrogus Schönherr are newly placed in sonynymy with Tychius; Lepidotychius Penecke is considered a subgenus of Tychius. All known host plants of species of Tychius are members of the legume subfamily Papilionoideae. Species from South America and Australia described as Tychius were not correctly assigned and belong in other tychiine genera or in other subfamilies.