Cryptosporidiosis, a zoonotic diarrheal disease, significantly contributes to the mortality of people with impaired immune systems worldwide. Infections with an animal-adapted genotype (Genotype 2) of Cryptosporidium parvum were found in a human population in Uganda that shares habitats with free-ranging gorillas, from which the same genotype of C. parvum had been recovered previously. A high prevalence of disease was found in park staff members (21%) who frequently contact gorillas versus 3% disease prevalence in the local community. This indicates a zoonotic transmission cycle of this pathogen against which no effective prophylaxis or therapy exists. The results of the study questionnaire demonstrated a high percentage of people not undertaking appropriate precautions to prevent fecal-oral transmission of C. parvum in the Bwindi Impenetrable National Park, Uganda. This human population will benefit from stronger compliance with park regulations regarding disposal of their fecal waste within the park boundaries.