Background & aims: Sarcopenia is a risk factor for adverse outcomes in older adults, but this has yet to be confirmed in chronic kidney disease (CKD). We conducted a systematic review to investigate the association between sarcopenia and its traits with mortality, hospitalization, and end-stage kidney disease (ESKD) progression in CKD patients. Methods: Five electronic databases were searched, including MEDLINE and Embase. Observational cohort studies with CKD patients were included. The sarcopenia traits assessed were low muscle strength, low muscle mass, and low physical performance, as well as diagnosed sarcopenia (combined low muscle mass and low strength/performance). Hazard ratios (HR), risk ratios (RR), odds ratios (OR), and 95% confidence intervals (CI) were pooled using random-effect meta-analyses. Results: From a total of 4922 screened studies, 50 (72,347 patients) were included in the review and 38 (59,070 patients) in the meta-analyses. Most of the included studies were in dialysis patients (n = 36, 72%). Pooled analyses showed that low muscle strength (15 studies; HR:1.99; 95%CI:1.65 to 2.41; I2:45%), low muscle mass (20 studies; HR:1.51; 95%CI:1.36 to 1.68; I2:26%) and low physical performance (five studies; HR:2.09; 95%CI:1.68 to 2.59; I2:0%) were associated with increased mortality risk in CKD patients. Diagnosed sarcopenia was also associated with the mortality risk in dialysis patients (eight studies; HR:1.87; 95%CI:1.35 to 2.59; I2:40%). On the other hand, it was uncertain whether low muscle mass was associated with hospitalization (two studies in dialysis patients; RR:1.81; 95% CI:0.78 to 4.22; I2:59%). Further, limited ESKD progression measures prevented meta-analysis for this outcome. Conclusions: Low muscle strength, low muscle mass, and low physical performance were associated with higher mortality in CKD patients. In dialysis patients, diagnosed sarcopenia also represented higher mortality risk. Evidence to conclude associations with hospitalization and ESKD progression is currently lacking. Prospero registration: CRD42020192198.