Osteoarthritides of the hip and knee represent two of the most important causes of pain and physical disability in the community. Recent studies have helped delineate the different patterns, rates of progression, and determinants of outcome in these two conditions. For example, patellofemoral and tibiofemoral osteoarthritis of the knee appear to have different associations and consequences; psychosocial factors and muscle strength seem to be the key determinants of pain and disability. These insights have contributed to a parallel development in new treatment strategies for established hip and knee osteoarthritis, including increased psychosocial support, educational and fitness programs, and different drugs and physical interventions. Therapeutic regimens geared to the specific needs of patients with lower limb osteoarthritis are emerging. They should replace the inappropriate application of treatments designed for inflammatory arthropathies to patients with osteoarthritis.