A new species of Pristella is described from the Río Meta drainage, Río Orinoco basin, Colombia. Pristella ariporo, new species, is described as the second known species of the genus and differs from P. maxillaris by lacking maxillary teeth, possessing all teeth of premaxilla and dentary conical, by the absence of a dark blotch on the pelvic fin and the absence of a humeral blotch. The evaluation of the relationships of the new taxon within Characidae through an extensive phylogenetic analysis recovered Pristella as a monophyletic clade, sister to Bryconella pallidifrons. A new diagnosis of Pristella is provided. Hyphessobrycon axelrodi, the only species of this genus possessing only conical teeth, may actually be a species of Pristella.