Background Liposomal amphotericin B is locally delivered to treat fungal orthopaedic infections but little is known about local tissue toxicity, if any, that might be associated with local delivery. Questions/purposes (1) Is liposomal amphotericin B cytotoxic in vitro? (2) Is locally delivered liposomal amphotericin B toxic to tissue in vivo? Methods Mouse fibroblasts (BA LB/3T3 A31) and osteoblasts (MC3T3) were exposed to two formulations of amphotericin B (liposomal and deoxycholate) at concentrations of 0, 1, 5, 10, 100, 500, and 1000 lg/mL. Cell viability was determined by MTT assay after 1, 3, and 5 hours of exposure and a proliferation assay after 1, 4, and 7 days of exposure and then after 3 recovery days without drug. Tissue exposure occurred by local delivery of liposomal amphotericin B, 200 or 800 mg/batch antifungalloaded bone cement (ALBC), or amphotericin B deoxycholate, 800 mg/batch ALBC in rat paraspinal muscles.White blood cell count (WBC) and serum amphotericin B levels were obtained on Days 1 and 3. Rats were euthanized at 2 and 4 weeks and semiqualitative histopathology was performed.