Rondonacara, gen. nov. is herein described as a member of the tribe Cichlasomatini, being considered as the sister taxon of Laetacara. The new genus differs from all the other genera of Cichlasomatini by having transversal streaks originated at the insertion of spines and softs rays of dorsal fin. Additionally, the new genus differs from the other genera of the Cichlasomatini by its unique combination of character states: longitudinal stripe of the flank horizontally oriented, ending directed to caudal-fin base; conspicuous suborbital bar; caudal-fin base spot on the middle of the fin and not ocellated; preopercle without scales; two supra-neural; and uniserial predorsal squamation. Rondonacara is monotypic, including only Rondonacara hoehnei, re-described herein. This species was originally described from a tributary of the Araguaia River, Mato Grosso state, with unprecise locality. Currently, Rondonacara hoehnei is known only from a single locality, a tributary of the das Mortes River, Araguaia River basin, in the Brazilian Cerrado. The restrict distribution area, and the widespread and accelerated destruction of natural habitat strongly indicate that Rondonacara hoehnei is critically endangered