BackgroundOral focal epithelial hyperplasia (FEH) is an uncommon infection affecting humans, chimpanzees, bonobos, and howler monkeys. This study describes 10 cases of free‐ranging brown howler monkeys (Alouatta guariba clamitans) diagnosed with FEH and Alouatta guariba Papillomavirus 1 (AgPV 1).MethodsWe analyzed demographic characteristics, rescue conditions, clinical and pathological findings, and species‐specific behavior factors in these cases. The study assessed the frequency of occurrence and potential contributing factors of FEH and AgPV 1 infection.ResultsThe frequency of FEH was 8.13%. Most affected howlers were adult or geriatric males with comorbidities or stressful conditions. Clinical and pathological observations were consistent with AgPV 1 infection. Species‐specific behaviors and environmental stressors were identified as contributing factors.ConclusionsFEH associated with AgPV 1 affected mainly adult or geriatric males with ongoing comorbidities or stressful conditions. Further research is needed to understand these factors for effective management.