The tadpole of Nymphargus grandisonae is described from Serranía de los Paraguas, Valle del Cauca-Colombia. Characteristics of clutches (i.e., position, coloration, number of ova) and ontogenetic variation, as well as some aspects of natural history of adult males, are provided. The tadpole of N. grandisonae differs from other centrolenid tadpoles in characteristics such as M-shaped upper jaw sheath, small gap in row A-2, and by having a non-emarginate oral disc. Although it has been proposed that the lack of morphological differences in glassfrog tadpoles is due to ecomorphological convergence, the number of tadpole descriptions based on feeding specimens is limited, as is the number of comparative studies of larval anatomy. Additional standardized studies of larval characters and subsequent phylogenetic analysis are required to test this hypothesis.