Benefits of a direct anterior approach (DAA) versus a posterior-lateral (PA) approach to THA were assessed in a single-surgeon, IRB-approved, prospective, randomized clinical study. Subjects (43 DAA and 44 PA) were evaluated at 6 weeks, and 3, 6 and 12 months. The primary end point was ability to climb stairs normally and walk unlimited at each time point. Secondary end points included assessment by several outcome instruments. DAA subjects performed better during the immediate post-operative period; they had lower VAS pain scores on the first post-operative day, more subjects climbing stairs normally and walking unlimited at 6 weeks, and higher HOOS Symptoms scores at 3 months. There were no significant differences between groups at later time points. Findings confirm previous reports of benefits of DAA versus PA in early post-operative phases. Copyright © 2013 Elsevier Inc. All rights reserved.