Background: The antifungal activity of coriander oil has already been demonstrated in vitro. Objective: Evaluation of the efficacy and tolerability of 6% coriander oil in unguentum leniens in the treatment of interdigital tinea pedis. Methods: Half-side comparative pilot study on subjects with symmetric, bilateral interdigital tinea pedis. Active drug and placebo control were applied twice daily on the affected areas, and follow-up visits were performed on days 14 and 28. Results: 40 participants (mean age 52.5 years, 60% male) were included in the study. For 6% coriander oil in unguentum leniens, a highly significant improvement of the clinical signs (p < 0.0001) was observed during the entire observation period; the number of positive fungal cultures also tended to decrease (p = 0.0654). The tolerability of the tested substances was good. Conclusion: Coriander oil is effective and well tolerated in the treatment of interdigital tinea pedis.