Osteoarthritis is the most common form of arthritis in the United States. It is estimated that 20 million Americans have arthritis, and the annual societal cost is $95 billion. Several exercise studies have shown modest improvements in disability, physical performance, and pain in subjects with knee osteoarthritis. While similar results have been suggested in hip osteoarthritis, well-designed randomized clinical trials have not been conducted. Exercise programs appear beneficial but without adherence, the beneficial effects of exercise for knee and hip osteoarthritis decline over time. A well-designed, evidence-based, arthritis-specific study controlling for exercise duration, frequency and adherence is needed. The objective of this study is to determine the effects of structured exercise programs on self-reported pain and disability in adults with hip osteoarthritis. This prospective, randomized study with a wait-list control is designed to develop preliminary data to support an R01 funding request for a large, randomized clinical trial. All exercise interventions and outcome assessments will take place at OHSU in the Orthopaedics and Rehabilitation Clinics, Rehabilitation Services physical therapy gym, and the General Clinical Research Center. Subjects will be selected to include individuals representative of the larger population with documented hip osteoarthritis. This three-month study will evaluate the effects of an aerobic and resistance exercise program on pain and disability in individuals with hip osteoarthritis. Outcome assessment will follow the Outcome Measures in Rheumatology (OMERACT) recommendations for a core set of outcome measures for clinical trials in arthritis and assess pain, physical function, patient global assessment, and joint imaging. Data analysis will focus on comparing pre- and post-intervention endpoints using conventional statistical analyses such as repeated-measure analysis of variance for repeated continuous measures (e.g. walking distance), and non-parametric methods such as Chi-square or frequency analysis for proportions (e.g. visual pain scores).