Study Objective. To understand the relationship between dosage and therapeutic response of amphotericin B lipid complex (ABLC) by analyzing underlying diseases, types of infections, and therapeutic outcomes with different dosages as second-line antifungal therapy. Design. Retrospective analysis of low-dose (initial dose less than or equal to 3 mg/kg) ABLC from three open-label, clinical, second-line treatment studies. Setting. Centers in the United States (204), Canada (3), Australia (I), Mexico (1), and The Netherlands (I). Patients. Five hundred fifty-one patients (5 enrolled twice) with invasive fungal infections, of whom 289 failed and 267 were intolerant to conventional antifungal therapy. Interventions. Patients were to receive the recommended dosage of ABLC 5 mg/kg/day, with dosage reduction for markedly increased serum creatinine. The duration of treatment was 4 weeks; therapy could be extended if the investigator considered additional treatment necessary. Measurements and Main Results. Seventy-three patients (13%) received ABLC 3 mg/kg/day (low dosage) instead of the protocol-recommended 5 mg/kg/day. Response was 65% and 56%, respectively. Logistic regression analysis revealed that the following patients are most likely to start therapy at the lower dosage: those with candidiasis and other yeast infections, patients with nephrotoxicity due to prior amphotericin B, and those with underlying conditions other than hematologic malignancy. Conclusion. These results suggest that ABLC 3 mg/kg/day may be effective in treating patients with candidiasis who do not have hematologic malignancy.