Primary palmer hyperhidrosis is a disabling problem that affect young ages and usually continues for years without an effective treatment. It is usually accompanied by planter hyperhidrosis and to lesser extent by axillary affection. We try to improve the efficacy of percutaneous radiofrequency ablation of upper thoracic sympathetic ganglia via imitating what thoracoscopic surgeons do in endoscopic thoracic sympathectomy. Patients and methods Forty patients of primary hyperhidrosis were randomly classified into two groups. Group Tb (N=20) underwent thermocoagulation of sympathetic chain on vertebral body. Group Th (N=20) underwent thermocoagulation of sympathetic chain on the head and neck of ribs. Hand temperature and dryness were followed up during the procedure and on the following intervals; one week, one month, 3,6,9 and 12 months after the procedure. Results During the procedure the hands of 50% of patients became warm and dry in group Tb and only 40 % completed till 12 months while in group Th the hands of 100% of the patients became warm and dry during the procedure till 12 months . Conclusion Thermocoagulation of upper thoracic sympathetic chain on the head and neck of the second and third ribs is more effective than attacking the chain on vertebral bodies in patients with primary hyperhidrosis with no recorded complications.