Communication is an integral part of animal behavior, impacting population structure and individual fitness and regulating spatial distributions. Scent marking is common among solitary, low-density, and wide-ranging carnivores, such as felids. Understanding the functional role of scent marking will inform our understanding of the behavioral ecology of carnivores. We investigated patterns of scent marking by pumas (Puma concolor) and jaguars (Panthera onca) via weekly surveys of trails for scrapes and documenting scent-marking behaviors and responses using motion-triggered video cameras. Jaguars mainly sprayed vegetation, whereas pumas mainly scraped the ground. Only a subset of individuals for both pumas and jaguars were responsible for the majority of scent-marking activity. On average, male pumas scraped more frequently (scrapes/km) than male jaguars, and the scrape rate of male pumas increased following the presence of potential mates and competitors. Male pumas returned to trails more quickly following the presence of conspecifics (potential competitors or mates) than in their absence, however, visitation by male jaguars increased in response to competitors only. A male puma detected travelling with three different females on separate occasions scraped more frequently than males who were not detected with females. This study suggests that jaguars and pumas are constantly assessing, and reacting to, the presence and marks of competitors and potential mates, facilitating the maintenance of complex social structures.