Interrelationships of 25 predefined groups, belonging to the genus Rivulus and its allied, are proposed after the phylogenetic analysis of 74 external characters using PAUP 3.1.1. software. The resulting consensus tree is congruent with previous, not all, analyses and with the biogeographical distribution. The taxa Pituna and Millerichthys are confirmed valid entities, distinctive from Rivulus, but their definite systematic position needs to be corroborated by further studies. The taxa Moema and Renova form a well supported monophyletic lineage with Trigonectes, and it is proposed they are downgraded to the subgenus level, under Trigonectes. Two new subgenera of Rivulus are described, Oditichthys and Laimosemion, which possess true distinctive characters within the genus.