What are the effects of physiotherapy exercise for patients with osteoarthritis after elective primary unilateral total knee arthroplasty? AMED, CINAHL, EMBASE, King's Fund, Medline, Cochrane library, PEDro, and the UK Department of Health national research register, searched up to April 2007. This search was supplemented by handsearching a small number of journals and conference abstracts, as well as scanning the reference lists from relevant articles identified by the search. Randomised controlled trials involving patients undergoing elective total knee arthroplasty for osteoarthritis in which organised physiotherapy after discharge from hospital was compared to standard post-discharge management. Outcome measures were function, range of motion, muscle strength, walking speed, and quality of life. : Two reviewers (masked to the key details of the papers) independently assessed methodological quality on a checklist developed from the CONSORT statement and the Critical Appraisal Skills Programme guidelines and extracted the data. Six trials with a total of 614 patients were identified, of which five trials with a total of 554 patients provided data that could be included in the meta-analyses. Trial quality was good overall. The trials compared additional physiotherapy exercises or treatment after discharge with no organised outpatient physiotherapy. The patients in the control groups were expected to continue with traditional home exercise programs: isometric strengthening, range of movement exercises, and gait training. Based on quantitative pooling of three trials at 3 to 4 months follow up, there were statistically significant differences in favour of physiotherapy exercises for function (standardised effect size 0.33, 95% CI 0.07 to 0.58) and range of motion (weighted mean difference 3 degrees, 95% CI 1 to 5). At the same time point, results from two trials indicated no significant difference in quality of life (weighted mean difference 1.7 points, 95% CI −1 to 4.3) or walking speed (standardised effect size 0.27 (95% CI –0.13 to 0.67). None of the trials measured muscle strength. At one year follow up, there were no statistically significant differences in any outcome. Additional physiotherapy exercises or treatment after discharge have small to moderate short-term beneficial effects compared to no organised outpatient physiotherapy.