Privilege conflicts and credentialing issues involving family physicians' care of hospitalized patients are controversial areas. This study compares the process and outcome of critical care provided by family physicians and general internists. We studied 523 patients admitted by these specialists to the medical intensive and cardiac care units of a large regional hospital over a one-year period. The length of stay and readmission rate in the intensive care unit and hospital, severity of illness, discharge diagnosis, proportion who died, time until death of those who died, consultation rate, and hospital charges did not differ significantly between patients cared for by physicians in the two specialties. Application of Cox's proportional hazard model to the data indicated the risk of death to be significantly related to patient race, age, and severity of illness, but not to physician specialty. Regression analysis of several morbidity variables showed no relationship to physician specialty. Lack of differences in outcome and process in the hospital studied leads us to believe that both family physicians and general internists are entitled to have equal access to the care of patients in critical care units.