We performed a pilot study to assess the safety and efficacy of pulse therapy with terbinafine tablets in 66 patients with dermatophyte onychomycosis. One pulse consisted of oral terbinafine tablets (500 mg/day) given for 1 week followed by a 3-week interval. Topical 1% terbinafine cream was applied daily. The number of pulses was determined by the extent of improvement in the affected nails and by the patient's requests, up to a maximum of six pulses. Efficacy was assessed based on both clinical and mycological examinations 1 year after treatment initiation. We observed a complete cure in 51 patients (77.3%), marked improvement in five patients (7.6%), improvement in five patients (7.6%) and slight improvement in one patient (1.5%). Four patients (6.0%) showed no change. In the patients who were completely cured, the average number of pulses used was 3.7 +/- 1.4 pulses and the treatment duration was 3.3 +/- 1.6 months. Nine patients experienced adverse effects, consisting of gastrointestinal disturbance (eight patients) and drug-induced eruption (one patient). There were no abnormal findings in the laboratory tests, including liver function tests. In summary, terbinafine pulse therapy in combination with topical application of terbinafine cream appeared safe and effective in this pilot study.