In the literature, there are a few numbers of studies on the effectiveness of acetic acid iontophoresis (AAI) in the treatment of calcifying tendinitis of the shoulder. In this case report, our aim is to show the effectiveness of AAI in a patient with calcific tendinitis of the shoulder showing resistance to conservative treatment and to review the related literature. A 48 year old male patient presented with pain and limitation of left shoulder movements, on his examination flexion, abduction, internal and external rotation of the left shoulder was painful and restricted. Calcifying tendinitis was detected with direct radiography and magnetic resonance imaging. Upon persistence of symptoms after physical and exercise therapy, AAI was applied for 25 sessions. Exercise programme was given during AAI treatment Painless and full active ranges of motion of shoulder in all planes were gained with treatment of AAI. A decrease in the size of calcification compared to pretreatment period is detected with direct radiography. The patient has not any complaint after 12 months of follow up. In our opinion, AAI can be used as a non-invasive alternative treatment in patients with calcifying tendinitis of the shoulder