Background: The number of primary knee arthroplasties (KAs) performed annually is rising, especially among active, working age patients. Consequently, revision KA is also increasingly performed. Our aim was to systematically review the extent to which patients were physically active following revision KA, and the rate and timing of return to sport and work., Methods: A search was conducted in the databases Medline and Embase until February 24 th , 2023. Studies describing patients with revision total knee arthroplasty (rTKA) or revision unicondylar knee arthroplasty (rUKA), with outcomes regarding physical activity or return to sport (RTS) or work (RTW) were included. Quality of studies was assessed using the Newcastle-Ottawa scale, meta-analyses were performed using RevMan 5.4 and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE)., Results: Of the 4,314 articles screened, 22 studies were included describing 2,462 rTKA patients (no rUKA), 42% were male with a mean age of 67 years (range 24 - 95). No studies reported objective physical activity measurements. Twenty-two studies reported patient reported outcome measures (PROMs). The PROMs that were pooled on a scale from zero to ten were the UCLA Activity Score, the Tegner Activity Level Scale, the Lower-Extremity Activity Scale, Devane Activity Score, and physical activity related subscales of the Knee injury and Osteoarthritis Outcome Score. The retrospective studies of moderate quality showed a statistically significant postoperative improvement of 1.7 points (MD = 1.71, 95% CI 1.48 - 1.94 (p < 0.0001); 14 studies, n = 1,211). For the prospective moderate-quality studies, a statistically significant postoperative increase of 0.9 points was found (MD = 0.89, 95% CI 0.48 - 1.30 (p < 0.0001); 6 studies, n = 1,027). Regarding RTS, 12% of patients participated in so-called 'non-recommended' activities (i.e., hockey, soccer, football, gymnastics, jogging, singles tennis, and basketball) after rTKA (1 study, n = 206). The pooled RTW was 86% (2 studies, range 18-95%, n = 234)., Conclusions: The majority of patients self-reported an improved postoperative activity level after rTKA. Patients could maintain an active lifestyle in daily life, including sports and work. For reliable physical activity, RTS and RTW estimations, more studies are required. In terms of GRADE, the quality of evidence for the five prospective studies was rated as low., Level of Evidence: Level 3., (© 2023. The Author(s).)