Invasive aspergillosis remains associated with significant morbidity and mortality, necessitating new options for salvage therapy. The objective of this study was to evaluate the efficacy and safety of micafungin as salvage monotherapy in patients with invasive aspergillosis. Patients with proven or probable invasive aspergillosis, who were refractory or intolerant to previous systemic antifungal therapy, were randomised 2 : 1 to receive 300 mg day−1 intravenous micafungin monotherapy or an intravenous control monotherapy [lipid amphotericin B (5 mg kg−1 day−1), voriconazole (8 mg kg−1 day−1) or caspofungin (50 mg day−1)] for 3–12 weeks. Patients underwent final assessment 12 weeks after treatment start. Seventeen patients with invasive aspergillosis (proven, n = 2; probable, n = 14; not recorded, n = 1) participated in the study (micafungin arm, n = 12; control arm, n = 5). Three patients each in the micafungin (25.0%; 95% CI: 5.5–57.2) and control arm (60.0%; 95% CI: 14.7–94.7) had successful therapy at end of treatment as assessed by an Independent Data Review Board. Eleven patients died; six due to invasive aspergillosis. No deaths were considered related to study treatment. During this study it became increasingly common to use combination treatment for salvage therapy. Consequently, enrolment was low and the study was discontinued early. No clear trends in efficacy and safety can be concluded.