1 Lincomycin (600 mg) was given 6 h preoperatively by intramuscular injection, as an intravenous infusion over 30 min and for 72 h postoperatively in twelve patients having total hip replacement. 2 The plasma, bone, hip capsule, synovial and drain fluid concentrations of lincomycin were almost always above the M.I.C. of lincomycin against penicillinase producing Staphylococcus aureus. 3 There was a good correlation between the estimated concentrations of lincomycin in bone by the grinding and agitation methods of analysis. 4 Two patients developed pseudomembranous colitis after parenteral lincomycin.