Neotropical puma (Puma concolor) diet is scarcely known, in particular that of mountain dwelling individuals from Northern South America. This is the first study on pumas from the paramo and the first puma diet analysis for Colombia. The puma diet was studied from 2007 to 2009 in the Puracé National Park in the South Colombian Andes. Paramos are unique neotropical high altitude ecosystems which store and regulate water, and are currently threatened by agricultural expansion and climate change. Seven latrines were monitored for three years and scat collected, washed and dried. Items in scat such as hair, bones, claws and others were separated. Hairs were inspected by microscopy and compared to voucher hair museum specimens. Bone fragments, claws and teeth were also compared to museum collections and identified wherever possible. Additionally, six cameras were set along game trails to document puma and potential prey presence in the area. Food items from five species were identified in 60 puma scats; Northern Pudu (Pudu mephistophiles) was the most important prey in their diet. A total of 354 camera trap-nights photographed a male and female puma, Northern pudu and Spectacled bear (Tremarctos ornatus). The main conclusion suggests a strong dependence of puma on the threatened and mysterious Northern Pudu in paramo habitats. This behavior might reflect restricted prey availability in the high Andes mountains of Colombia, and highlights the plasticity in the puma diet. Conservation actions in the paramo should thus, focus on focal wild species, and in particularly those that show a relationship, such as the one evidenced here with the dependence of puma on Northern Pudu. These findings contribute to increase the little known ecology of Andean puma populations and the species as a whole in Colombia. Baseline data on puma prey populations in different ecosystems throughout their range, is critical to understand the regional requirements for survival, and design conservation actions, to follow and evaluate the need for particular protected areas along their geographical gradients.