Along the Rio Manu in southeastern Peru, Round-tailed Manakins (Pipra chloromeros) breed mainly from August to November. Male P. chloromeros have a dispersed lek breeding system, with each lek composed of two to five territorial males. Sites used by males for display had significantly higher densities of shrubs, vines, and small trees than did non-display sites. Interlek distances ranged from 220 to 1000 m. Within leks, most males occupied territories within auditory range, but not visual range. Distance to the closest neighbor's display perch varied from 8 to 87 m. Males vigorously defended territories that ranged from 20 to 50 m in diameter. Males progress in social status within the lek (from immature to non-territorial adult to territorial adult). Territorial adult males were always dominant to males of the other two categories. Territorial males engaged in daily ritualized encounters at the borders of their territories. Encounters involved slow, coordinated displays reminiscent of those performed toward females. Such interactions may help maintain dominance relationships within the lek, but an analysis of interaction outcomes failed to show clear dominance relationships among males. Female visitation was most frequent in early afternoon, during males' maximum territory attendance and display activity. Lekking P. chloromeros employ ten display elements, six vocalizations, and one mechanical noise. One display element has not been observed in any other species of Pipra. The displays and sounds in the P. erythrocephala clade are compared from the perspective of understanding the evolution of display behavior in this group.