We report chromosome counts for ten taxa of Vincetoxicum sensu stricto (s. str.) (Apocynaceae) from Turkey (of which two are endemic), including the first chromosome counts for V. canescens subsp. pedunculata, V. funebre, V. fuscatum subsp. boissieri, V. parviflorum and V. tmoleum. Two taxa of V. fuscatum proved to be tetraploid (2n=44) and the remaining eight taxa diploid (2n=22). Molecular phylogenetic analyses based on nrDNA (ITS) and cpDNA (trnT-trnL) (including 31 newly generated sequences) confirm the position of the Turkish Vincetoxicum in the Vincetoxicum s. str. clade. Vincetoxicum fuscatum, V. parviflorum, V. speciosum, as well as the Turkish endemic V. fuscatum subsp. boissieri, were clearly resolved as species-level clades, whereas the delimitation of the rest of the Turkish taxa was less clear based on molecular data.