The Chilean Patagonia is characterized by extensive protected areas that encompass most of the region. Mammals are often among the priorities for these protected areas either as conservation targets (e.g., threatened species) or as threats (e.g., invasive species). Camera traps offer a cost-effective alternative to monitor these species, however baseline studies are scarce in the region. Therefore, our objective was to provide an assessment of camera-trapping detection rates for mammals that are present in protected areas of Magallanes, Chilean Patagonia. Between 2015 and 2022 we installed 278 camera traps (9,936 trap-days), distributed in seven protected areas. For each protected area, we calculated the detection rates and proportion of camera traps that detected each species. We recorded 18 mammalian species, including ten native, four domestic, and four invasive species. The culpeo fox (Lycalopex culpaeus) was the most frequently detected species, followed by invasive European hare (Lepus europaeus) and puma (Puma concolor). Endangered species like the huemul (Hippocamelus bisulcus) and southern river otter (Lontra provocax) were detected infrequently, whereas beaver (Castor canadensis) and American mink (Neogale when species of interest are associated with specific features of the landscape (e.g., otters and water), other designs are needed. Based on our findings, we provide recommendations for the design of camera-trapping monitoring plans in protected areas.