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Rivulus cearensis, new species, from Sao Goncalo do Amarante, Ceara, northeastern Brazil, is described. It was found in a shallow stream within a residual humid forest inserted in the semi-arid Caatinga region. The new species seems to be closely related to R. bahianus and to the species of the R. urophthalmus group by all having the ventral surface of head entirely covered by scales and flank with horizontal rows of small reddish brown or red spots in males; it differs from all those species by possessing iris green and by the absence of the ventral process of the posttemporal bone. It is also distinguished from R. bahianus by having more robust body and a broad dark red stripe oil the dorsal and ventral margins of the caudal fin in males, and from species of the R. urophthalmus group by having fewer scales in the longitudinal series and scales extending over about 40-50% of the caudal fill.