Characterizing a species' feeding habits has proved key to delimiting critical areas for species conservation. The Andean bear (Tremarctos ornatus), a species of conservation concern, inhabits the montane cloud forest and montane grasslands (jalca) of Amazonas, northeastern Peru. Knowledge of the bear's diet there is limited. Thus, we aimed to determine whether contents of Andean bear scat there differed between the rainy and dry seasons of 2016. Microhistological analysis of scats, with reviews on its feeding sites, showed a mainly herbivorous generalist diet dominated by Bromeliaceae, Ericaceae, and Lauraceae. Scat contents differed between seasons, possibly associated with the phenology of consumed vegetation. Persea sp. aff. areolatocostae was a key species in the seasonal changes. Our results suggested that the bears at this site may be opportunistically frugivorous, changing their diets in response to food availability.