We investigated the effects of anidulafungin alone and in combination with amphotericin B against Aspergillus fumigatus. Indifference was the only type of interaction observed in vitro. Anidulafungin at 1 and 5 mg/kg of body weight/day, amphotericin B at 1 mg/kg/day, and combination therapy prolonged the survival of mice with invasive aspergillosis. Anidulafungin at 5 mg/kg/day, alone and in combination with amphotericin B, reduced the kidney fungal burden. Overall, the combination was not superior to the most active single drug.