Primary hepatic non-Hodgkin's lymphoma (NHL) is a rare disease that presents unique diagnostic and therapeutic challenges. Secondary liver involvement by lymphoma is common and can complicate treatment decisions. A review of the published case reports and the few larger series suggests that primary hepatic NHL represents a heterogeneous mixture of disparate diseases rather than a single entity. Presentations vary from the incidental discovery of hepatic abnormalities in an otherwise asymptomatic patient to that of fulminant hepatic failure with rapid progression of encephalopathy to coma and death. The clinical, laboratory, and radiographic characteristics are nonspecific, which means the diagnosis is often not suspected until histopathologic examination of liver tissue. There appears to be a strong association between primary hepatic NHL and the hepatitis C virus. Hepatosplenic T-cell lymphoma has attained its own status as a unique disease, whereas case reports suggest that the spectrum of hepatic lymphoma includes many histologies. Involvement of the liver by lymphoma can compound the difficulty of pursuing aggressive chemotherapy in patients who have a life-threatening illness and impaired metabolism of the most effective drugs. Therapy should be tailored to the individual clinical situation, with consideration of the underlying histology and degree of hepatic insufficiency.