BACKGROUND: Essential hyperhidrosis is a pathologic condition caused by excessive secretion of the eccrine sweat glands. This is an embarrassing condition, which severely reduces the quality of life and may result in psychological disturbance. Our purpose was to determine the therapeutic efficacy of oral glycopyrrolate in term of its strength, safety, and side effects. METHODS: Oral glycopyrrolate was given to 104 patients, 53 men and 51 women with a mean age of 24 years. Patients controlled the dosage of glycopyrrolate for a week. Attention was focused on patient satisfaction, onset time, duration, degree of reducing perspiration and side effects. RESULTS: Ninety eight of 104 patients (94%) were satisfied with their improved condition. The most common maximum dose/day was 2 mg. The overall mean onset time was 2.3 hours and the duration of the effect was 7.4 hours. Dry mouth occurred in 40 patients. Sixty eight of patients (65%) experienced reduced excessive sweating caused by oral glycopyrrolate. CONCLUSIONS: The administration of oral glycopyrrolate is a safe and effective method of treating essential hyperhidrosis, and appears to be an acceptable therapeutic option in any form of hyperhidrosis.