The objective of this report is to summarize the medical literature relevant to the epidemiology, diagnosis, treatment, and control of hantavirus pulmonary syndrome (HPS). The English language literature was searched from January 1993 through March 1995, manually and using Medline, including conference proceedings and reference lists. We selected relevant articles on clinical aspects of HPS. HPS is a newly described illness that progresses through three phases: prodromal, cardiopulmonary, and convalescent. Its hallmark is the rapid progression from nonspecific prodromal symptoms to respiratory insufficiency caused by noncardiogenic pulmonary edema. Unlike other hantavirus infections, renal involvement and hemorrhagic manifestations are not dominant features in HPS. Treatment is based on close intensive care monitoring, oxygen, and cardiovascular support with inotropic and vasopressor drugs. Preventive measures include avoiding contact with rodents and their excrement. Peromyscus maniculatus is the primary rodent vector for the Sin Nombre virus, which caused the epidemic of HPS in the southwest United States in May 1993. HPS has a unique set of clinical findings and is caused by a genetically distinct hantavirus. Physicians and other health professionals should consider this disease when evaluating patients with unexplained respiratory insufficiency after a febrile prodrome, especially when history suggests possible rodent contact. Sporadic cases and possibly epidemics of HPS are likely in the future, particularly when ecological changes increase the population of infected rodent vectors in an area.