Microbates cinereiventris is a polytypic and widely distributed species. Its reproductive behavior is only known based on the description of a single nest. Here, we present the first description of the eggs and nest of the subspecies M. cinereiventris peruvianus and the first description of the nestlings, feeding, and incubation behavior for the species. M. cinereiventris peruvianus has an open nest, primarily made of dry plant fibers and green moss. Nest attentiveness was 92.31 ± 0.20%, and a total of eight trips were recorded during the last 2 days of incubation. Nestlings hatched naked, were fed 1.58 ± 0.89 times per hour by both parents, and grew at a rate of 0.83 g per day during the first 5 days. M. cinereiventris share nesting characteristics with closely related species (M. collaris and Ramphocaenus melanurus).