In an open, randomized, clinical study of toenail onychomycosis with matrix area involvement, two alternative regimens of topical amorolfine/oral itraconazole therapy were compared with itraconazole monotherapy. A total of 131 patients were randomized to treatment. Patients in the combination groups were treated with amorolfine 5% nail lacquer (Loceryl, Galderma Laboratories) once weekly for 24 weeks and 200 mg itraconazole once daily for 6 weeks (Group AI-6) or 12 weeks (Group AI-12). A control group received itraconazole monotherapy for 12 weeks (Group 1-12). Strict inclusion criteria specified that subjects had to have onychomycosis of the toenails with matrix area involvement and/or > 80% total nail surface involvement. Mycological evaluations using both microscopic examination and culture of nail samples were performed at weeks 12 and 24. A stringent assessment of outcome at study end combined the results of mycological and clinical outcomes into a global cure rate. Safety was also assessed. At week 12, mycological cure was attained in 42 of 45 patients (93.3%) in group AI-6, 29 of 35 patients (82.9%) in group AI-12, and 14 of 34 patients in group 1-12. The difference between both combination groups and the control group were significant (P < 0.001). The global cure rate at week 24 was 83.7% (36 patients) in group AI-6, 93.9% (31 patients) in group AI-12, and 68.8% (22 patients) in group I-12. The difference between the AI-12 group and itraconazole monotherapy was significant (P < 0.05). These results indicate that amorolfine combination therapy represents an improved treatment strategy for patients with severe onychomycosis.