123 patients suffering from axillary hyperhidrosis have been operated on as outpatients under local anaesthesia, with radical ablation of sweat glands. All except 7 patients were satisfied with the result. There were few complications. A group of patients and controls were extensively studied including quantitative sweat testing and axillary biopsis. Apart from increased axillary sweating during the test, no differences could be found. The basic etiology of the condition is still unknown.