Intraguild competition may be reduced if ecologically similar species segregate temporally. Using data from 1,596 camera-trap photos, we present the 1st quantitative analyses of the activity patterns of Andean cats (Leopardus jacobita), Pampas cats (Leopardus colocolo), culpeos (Lycalopex culpaeus), and pumas (Puma concolor) in high-altitude deserts of the Andes. We compared daily activity patterns for these carnivores with those of mountain vizcachas (Lagidium viscacia), the main prey of Andean cats. Activity patterns of all species were positively skewed toward night. Pampas cats displayed the greatest proportion of nocturnal activity, whereas Andean cats were the most diurnal. Activity of Andean cats differed significantly only from that of Pampas cats; Pampas cats also differed from pumas. Activity of Andean cats was generally similar to that of mountain vizcachas. The dissimilar activity patterns of Andean and Pampas cats support the hypothesis of temporal niche segregation of these felids.