A total of 382 patients with foot mycosis were entered into a dose-finding study. Patients were randomly treated with amorolfine spray 0.5% or 2% (double-blind) or cream 0.5% (open; used as a reference agent). The spray or cream was applied once daily for 4 weeks on average. At screening, in 348 patients evaluable for efficacy, a total of 381 fungi were isolated: Trichopyton rubrum (196), T. mentagrophytes (73), other dermatophytes (17), Candida albicans (65), other yeasts (23), and moulds (7). In 33 patients the fungal infection was mixed. Two weeks after the end of treatment, the culture was negative in 94.1% and 97.4% of patients treated with 0.5% or 2% amorolfine spray, respectively. The difference was not statistically significant. In the 0.5% cream group the culture was negative in 86.6% of patients. Nine out of 380 patients evaluable for safety had local adverse events: four (3.2%) in each of the spray groups, and one (0.8%) in the cream group. The most common local adverse events in the patients treated with spray were a burning sensation and dryness of the skin. In conclusion, both spray concentrations were highly efficacious and well tolerated. Further studies should show if more widely spaced treatment with amorolfine spray is as effective as daily administration.