Allobates paleovarzensis is a diurnal leaf-litter anuran of the Dendrobatoidea superfamily inhabiting Amazonian forests. Based on behavioral field observations, conducted between 2008–2017 at three localities, we describe the courtship, mating, parental care behavior and territoriality of the species. Vocal activity is more intense in the morning and during the rainy season. Resident males respond aggressively to other males that invade their territories, whereas females are not territorial. Females are attracted by the advertisement call of males and enter their territories to breed. The male courtship call has a lower frequency than the advertisement call, indicating that males can modulate the frequency characteristics of their vocalizations. Amplexus stimulates the release of oocytes by females. Males attend multiple egg clutches within their territories and transport tadpoles on their backs to aquatic habitats. Males carry up to 60 tadpoles on a single transport event—the largest number ever recorded for Allobates. We did not record male nor female cannibalism of tadpoles. In summary, we found that Allobates paleovarzensis is a polygamous species with uniparental care performed by the male, complex courtship behavior, high fecundity, and territoriality related to male competition for space and females.