The genus Lanio is distributed from southern Mexico to northern Brazil. Until now, nesting information has been limited and scattered among Lanio species. Nests descriptions are available for 3 of the 4 species, and only L. versicolor has nestling descriptions. No information is available on incubation and feeding behavior or incubation and nestling periods for any Lanio species. We present detailed nesting biology information for L. versicolor, such as incubation and nestling behavior, eggs and nest thermal dynamics, and nestling feeding behavior, and also present the first evidence of cooperative breeding for the genus Lanio based on 11 nests monitored in the buffer zone of Manu National Park, Cusco, Peru. Nests were cup-shaped, and all had a leaf located above the nest. The clutch size was 2 eggs, white with maroon or wine-colored spots covering the shell surface. Incubation and nestling periods were 15 and 11 d, respectively, and daytime nest attentiveness was 78%. Nest architecture, clutch size, and nestling period were consistent with previous reports for the genus Lanio. We found similarities in the nesting biology of Lanio spp. with other species of the Tachyphoninae subfamily. Our study significantly increases the information available for the genus Lanio and provides novel and important information of cooperative breeding for a Neotropical mixed-species flock “leader” species. Yet, more studies are needed to fill the large information gap on nesting of tropical birds such as the species in the genus Lanio.