We have retrospectively investigated clinical profile, efficacy, and safety in 41 patients who were treated with liposomal amphotericin B (L-AMB) in Aichi Medical University Hospital between January 2008 and June 2009. It turned out that L-AMB was used for severe infectious diseases and 31.7% cases discontinued L-AMB therapy because of death. L-AMB was administered as the second-line therapy in 56.1% (23/41), and was not effective in 48.8% (20/41). L-AMB was administered as the first-line therapy in 43.9% (18/41); (1) 1 for cryptotoccal infection, (2) 7 for severe sepsis or septic shock, (3) 2 for the case which cannot remove medical device and might have biofilm formation, (4) 6 for the induction of step-down therapy concept, (5) 2 for febrile neutropenic patients who have needed aggressive empiric therapy. There was no significant difference in serum potassium level (p = 0.10) and serum creatinine level (p = 0.05) between pretreatment and posttreatment with L-AMB. The serum creatinine level before initial treatment with L-AMB was 1.31 +/- 1.30 mg/dL. The patients for 7.3% (3 cases) had dialyzed before initial treatment with L-AMB, however, there was no case who need dialysis after administration of L-AMB. As for the highest creatinine level in L-AMB administered cases, 29.3% (12/41) and 24.4% (10/41) were normal to abnormal, and abnormal to abnormal, respectively. This is the first investigational report when the serum creatinine level before initial administration of LAMB had been abnormal. The other antimicrobial agents, which might have influenced renal function, were administered to 51.2% cases (21/41). That means the cases administered L-AMB might have other bacterial infections. As for the serum creatinine level, we observed the changing cases and the cases which did not cause the change at all regardless of the administering period of LAMB. The serum potassium level before initial administration of L-AMB was 4.1 +/- 0.8 mEq/L, concomitant use of furosemide etc. was 31.7% (13/41), the lowest serum potassium level was 3.4 +/- 0.9 (1.9-6.2)mEq/L in during using L-AMB, the serum potassium was 34.1% (14/41) in replenish potassium during administration of L-AMB, and the total replenished potassium was 131.25 mEq. We did not observe the case who had died because of the low potassium. Since L-AMB was the only fungicidal drug, when we use L-AMB for the serious infectious diseases to make the best use of the characteristic, we have to pay attention to the concomitant medication, renal function and the serum potassium level.