Two patients who developed cholestatic liver disease after exposure to antibiotics are described. One patient who received clindamycin had liver biopsy findings of marked cholestasis, portal inflammation, bile duct injury and bile duct paucity (ductopenia). A second biopsy after clinical improvement showed resolution of cholestasis but persistence of duct paucity. Three years later, treatment with ampicillin caused another episode of cholestatic hepatitis with cholestasis and duct paucity on rebiopsy. The second patient, who developed cholestasis after receiving trimethoprim-sulfamethoxazole, had marked duct paucity in the liver biopsy. This is the first description, to our knowledge, of ductopenia apparently caused by clindamycin. Cross-reactivity between clindamycin and ampicillin is also demonstrated in one patient. This report documents that duct paucity may occur within 10 days of onset of jaundice and appears to be confined to ducts less than 0.03 mm in diameter.