Here, we evaluated the clinical aspects and environmental factors for five cases of pneumocystosis in the eastern Brazilian Amazon. Pneumocystosis was associated with human immunodeficiency virus (HIV) infection, male sex, age (until 30 years), and treatment with sulfamethoxazole plus trimethoprim in 100%, 80%, 40%, and 80% cases, respectively. Drier months, higher temperatures, and wind speed were favorable variables for pneumocystosis. Overall, this fungal infection may be related to global warming, resulting in an increased occurrence of cases.