<p>Nephrectomy is standard for kidney tumors and living kidney donation, but postoperative chronic kidney disease (CKD) is a critical determinant of long-term outcomes. Risk factors for incident CKD after unilateral nephrectomy remain incompletely synthesized. PubMed, Embase, Web of Science, and Google Scholar were systematically searched from inception to January 2026. Eligible studies were adult cohort studies of patients with preserved preoperative kidney function (estimated glomerular filtration rate [eGFR] ≥ 60 mL/min/1.73&#xa0;m²) undergoing unilateral nephrectomy. Study quality was assessed using the Newcastle-Ottawa Scale (NOS). Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed- or random-effects models, as appropriate. Subgroup, leave-one-out sensitivity, and publication-bias analyses were performed. A total of 26 studies comprising 13,321 patients were included. Advanced age, male sex, diabetes mellitus, lower preoperative eGFR, higher preoperative serum creatinine, and radical nephrectomy were all significantly associated with an increased risk of postoperative CKD. In contrast, higher baseline eGFR was associated with a reduced risk. Each one-year increase in age was associated with a higher likelihood of CKD (adjusted OR = 1.05, 95% CI: 1.03–1.08). Compared with partial nephrectomy, radical nephrectomy significantly increased the risk of CKD (adjusted OR = 3.73, 95% CI: 2.27–6.13). Sensitivity analyses confirmed the robustness of the findings, although publication bias was detected for certain variables. Advanced age, diabetes, lower preoperative kidney function, and radical nephrectomy were associated with a higher risk of CKD after unilateral nephrectomy. Preoperative risk assessment, nephron-sparing surgery when oncologically appropriate, and risk-adapted follow-up may help reduce the postoperative CKD burden.</p>