Bone marrow and liver biopsy specimens from five patients with documented Q fever were reviewed. Eight bone marrow and two liver specimens had been obtained from eight days to two months after the onset of symptoms in the five patients. Three had Q-fever hepatitis; one had Q-fever endocarditis. The classic "doughnut" granulomas of Q fever were present in either the liver or initial bone marrow biopsy in all four of the untreated patients. It was recognition of the classic granulomas that prompted serologic studies for Q fever in three of the four patients.