Cyriocosmus peruvianus sp. nov., C. itayensis sp. nov., C. aueri sp. nov., C. giganteus sp. nov. from Peru, Loreto region, C. hoeferi sp. nov. from Brazil, C. williamlamari sp. nov. and C. nicholausgordoni sp. nov. from Venezuela are described, illustrated, diagnosed and both sexes, if known, keyed. New Peruvian species can be distinguished from all congeners, except C. bertae Pérez-Miles, 1998 and C. pribiki Pérez-Miles and Weinmann, 2009, by the uniformly coloured carapace and abdomen without stripes and by the short paraembolic apophysis in male palpal bulb. The female of Cyriocosmus ritae Pérez-Miles, 1998 is described for the first time from a known Peruvian population near Iquitos.