This booklet was intended to assist safety and health professionals, environmental consultants, supervisors, and others with direct or indirect responsibility for the health and safety of workers in understanding what histoplasmosis is, recognize activities with risks for exposure to Histoplasma-capsulatum, and learn ways to protect themselves and others from exposure. Anyone working at a job or present near activities where material contamination with H- capsulatum becomes airborne can develop histoplasmosis if enough spores are inhaled. Methods of diagnosing histoplasmosis were described, and information was provided on jobs and activities that may put people at risk for exposure to spores of H-capsulatum. A partial listing of occupations where exposure is possible included bridge inspectors or painters, chimney cleaners, construction workers, demolition workers, farmers, gardeners, heating and air conditioning system installer or service persons, microbiology laboratory workers, pest control workers, restorers of historic or abandoned buildings, roofers, and spelunkers. Methods of reducing exposure to H-capsulatum were discussed, including excluding bats and birds from buildings, controlling aerosolized dust, disinfecting contaminated material, disposing of waste, and wearing personal protective equipment. Other infectious agents to which workers disturbing bat droppings and bird manure may be exposed were also discussed. Fact sheets on histoplasmosis were provided in English and Spanish.