Exercise has generated interest as an important nonpharmacological treatment for symptomatic osteoarthritis (OA) of the hip and knee. Effect sizes in exercise interventions are small to moderate for pain and functional improvements and are similar to those observed for improvement in pain for nonsteroidal anti-inflammatory drugs (NSAIDS). However, in contrast to NSAIDS, exercise interventions are safe and improve function through a direct effect on muscle strength and function. Both aerobic and strengthening exercises seem to be equally effective in regard to pain and function in patients with OA. In obese patients with OA, a combination of diet and exercise may be advantageous for optimal benefits in health-related quality-of-life and physical function. This article will focus on recent (September 2001-August 2002) randomized controlled trials with exercise as an intervention in patients with OA.