Sokeikakketsuto was administered to 33 patients with recurrent cramps of the calf appearing once a week or more and persisting for 2 weeks or more. Treatment response was evaluated 1 month after the start of drug therapy. Patients whose cramps disappeared immediately after starting were regarded as showing a complete response, those with disappearance after 1 month as showing a partial response, those with a reduction to <50% after 1 month as showing a slight response, and those in whom 50% or more of cramps persisted after 1 month as showing no response. A complete response was achieved in 12 patients, a partial response in 11, a slight response in 9, and no response in 1. In 23 (69.6%) of the 33 patients, cramps disappeared within 1 month after the start of drug therapy. In 32 (96.9%), there was a reduction to <50%. In 29 (87.8%) of the 33 patients, cramps disappeared within 3 months, suggesting the efficacy of this drug. Two-package administration in the evening/at bedtime was more effective than 1-package administration for controlling cramps of the calf at night until early in the morning. The intensive pre-attack administration of 2 packages before sleep was the most effective. Sokeikakketsuto may be useful for treating recurrent cramps of the calf.