© 2015 by Begell House, Inc. Background. The aim of this prospective cohort study was to assess whether a relationship exists between acute postoperative pain after radial head arthroplasty (RHAP) and chronic functional impairment (CFI) 2 years after surgery. Methods. A total of 59 patients who underwent RHAP for acute radial head fractures were included in the study. Pain subscale of the condition-specific American Shoulder and Elbow Evaluation Instrument (ASES-e) and the region-specific Disability of Arm, Shoulder and Hand (DASH) questionnaire at baseline (within 3 days of surgery) and at the 2-year follow-up were used to assess the relationship between acute postsurgical pain and CFI 2 years after RHAP. Stepwise regression modeling was used. Results. Higher baseline ASES-e pain subscale significantly improved the predictive ability of the regression model, accounting for 24.4% of variation. Patients with a score of 31.5/50 on the ASES-e pain subscale were four times more likely to experience reduced functional outcomes as indicated by their DASH score (≥20/100). Discussion. Acute postoperative pain predicts CFI at the 2-year follow-up after RHAP. Future multicenter prospective trials with large sample size are required to test the validity of the predictive model and cutoff score.