Core decompression of the humeral head has previously been used as a joint-preserving procedure for treatment of symptomatic osteonecrosis of the shoulder. In this article, we describe a new decompression technique, which involves multiple small-diameter (3-mm) percutaneous perforations. In our study population (early-stage disease), shoulder arthroplasty was avoided in all 15 patients (26 shoulders) for a mean follow-up of 32 months (range, 24-41 months). Of the 26 shoulders, 25 had successful clinical and functional outcomes (University of California Los Angeles shoulder score, >24 points), and 1 showed radiographic progression of the disease but has not needed further operative treatment. We compared our decompression results with those of a nonoperative historical control group, identified through a literature search. There was a 48% (143/299) rate of progression to arthroplasty in the control group at a follow-up ranging from 2 to 4.5 years. This outpatient, percutaneous perforations technique appears to be a low-morbidity method for relieving symptoms and deferring shoulder arthroplasty in patients with symptomatic osteonecrosis of the humeral head.