Type specimens of the Cryptocephalus species described from the Cape Peninsula, South Africa by Fabricius (1798) and Thunberg (1787, 1827) were examined. The following nomenclatorial changes are proposed: Cryptocephalus pustulatus Fabricius, 1798 = C. repandus Thunberg, 1827 syn. nov.; Cryptocephalus sexguttatus Fabricius, 1798 = C. sexguttatus Thunberg, 1827 syn. nov.; Cryptocephalus trifurcatus Thunberg, 1827 = C. laciniatus Suffrian, 1857 syn. nov.; Cryptocephalus sinuatus Thunberg, 1827 = C. meridionalis Clavareau, 1913 syn. nov. = C. capensis Jacoby, 1904 syn. nov.; Cryptocephalus octopustulatus Thunberg, 1787 = C. octopunctatus Olivier, 1808 syn. nov. = C. capensis Harold, 1872 syn. nov.; Cryptocephalus crux Thunberg, 1827 = C. denticulatus Suffrian, 1857 syn. nov. Lectotypes are designated for Cryptocephalus sinuatus Thunberg, 1827 and C. laciniatus Suffrian, 1857. The spelling of Cryptocephalus pustulatus is fixed. All the species are redescribed, photographed and illustrated. The primary homonym Cryptocephalus crux Gebler, 1848 is replaced by its oldest available synonym C. manchuricus Gressit & Kimoto, 1961.