Background: When the hands, axillae and soles of the feet are excessively perspirated, it can be debilitating. Type A botulinum toxin-A (BTX-A) prevents sweating by preventing sweat glands from releasing acetylcholine. Objective: This study aimed to assess role of Botulinum toxin type A injection versus placebo treatment of primary palmar hyperhidrosis. Patients and Methods: twenty four patients presented with primary palmar hyperhidrosis (PPH) were collected from Dermatology Outpatient Clinics, Zagazig University Hospital. Their left hands were treated by placebo and their right hands were treated using BTX-A injection. Results:Improvement of HDSS (score 4) regarding treatment modalities. HDSS (score 4) before treatment improved after to be 6.7%, 66.7%,8.3%,8.3% score 1, score 2, score 3, score 4 in right side treated with Botulinum toxin type A injection ,versus 16.7%, 33.3%,20.8%, in left side treated with placebo treatment. There was significant high percent of excellent response for Botulinum toxin type A injection among females and patients with delay onset of disease (p < 0.05). Conclusion: BTX injections appear to be more effective than placebo. It's still one of the most popular noninvasive cosmetic procedures, and neurotoxin. BTX is still an effective and predictable agent.