BACKGROUND There are limited data on Prosthesis of Antibiotic-Loaded Acrylic Cement (PROSTALAC) use for the treatment of infection following shoulder arthroplasty. We performed a retrospective review of our experience with the PROSTALAC in terms of infection eradication, complications, and outcomes. METHODS Twenty-eight patients with an infection at the site of a shoulder arthroplasty who were managed with the PROSTALAC were followed until eradication of the infection and maximum functional improvement. The average duration of follow-up was 27.6 months (range, twelve to sixty-nine months). In twenty-five of the twenty-eight patients, the PROSTALAC was created with antibiotic-impregnated cement, a standard humeral head mold, and a scaffold with either a one-third tubular plate or a 3.5-mm reconstruction plate. Three PROSTALAC implants had no scaffold. RESULTS Although all patients benefited from the use of the PROSTALAC, there were nine complications in eight patients (29%), with six additional unplanned surgical procedures being performed in this group. One patient had a dislocation, three had a fracture of the PROSTALAC, and five had recurrent infections requiring debridement and revision PROSTALAC placement. All fractures were associated with use of the semitubular plate. Twelve patients (43%), including two with revision PROSTALAC implants, were satisfied with pain relief and function and declined a second-stage procedure. With the exclusion of two patients who had a revision PROSTALAC implant, sixteen patients (57%) had a second-stage procedure; the procedures included ten reverse shoulder arthroplasties, three hemiarthroplasties, two total shoulder arthroplasties, and one resection arthroplasty. At the time of the latest follow-up, the average forward elevation of the shoulder was 77° (range, 30° to 130°). Fifteen patients had no or mild pain, eight patients had moderate pain, and five had severe pain. Patients with reverse total shoulder arthroplasties did not have improved function compared with the other cohorts. CONCLUSIONS The use of the PROSTALAC for the treatment of infection following shoulder arthroplasty is beneficial. Infection was initially eradicated in twenty-three (82%) of twenty-eight patients, more than half of our patients had mild or no pain, and 43% of patients declined a second-stage procedure because of acceptable function and pain relief. Conversely, five of twenty-eight patients had severe pain and five patients had persistent infection requiring additional surgery. The use of the reverse total shoulder arthroplasty did not appear to improve outcomes.