Background <p>Chronic kidney disease (CKD) is associated with poor psychological well-being. Whether early-stage CKD is a risk factor for suicide warrants further research.</p> Methods <p>This nationwide, retrospective, cohort study aimed to evaluate the risk of suicide in patients with early-stage CKD and identify the associated risk factors. A total of 3.945,198 individuals aged ≥ 19&#xa0;years who underwent the 2009 national health screening in South Korea were studied. Among them, 202,291 patients had early-stage CKD (estimated glomerular filtration rate (eGFR) ≥ 30 and &lt; 60&#xa0;mL/min per 1.73&#xa0;m² and/or dipstick albuminuria ≥ 1 +). The study outcome was suicide as confirmed by the nationwide death register based on death certificates.</p> Results <p>The study population had a mean age of 59 ± 15&#xa0;years, and 47% were male. We identified 930 suicides (incidence rate, 0.45 per 1000 person-years) in the CKD group and 11,332 suicides (incidence rate, 0.27 per 1000 person-years) in the non-CKD group. Early-stage CKD was significantly associated with an increased risk of suicide in multivariable analysis adjusted for demographic characteristics; lifestyle habits; comorbidities, including diabetes and hypertension; economic status; and depression, bipolar disorder, schizophrenia (hazard ratio, 1.18; 95% confidence interval 1.10‒1.26). Suicide incidence was higher in individuals with proteinuria but preserved kidney function (eGFR &gt; 60&#xa0;mL/min per 1.73&#xa0;m² and dipstick albuminuria &gt; 1 +) than in those without CKD.</p> Conclusion <p>Healthcare providers may need to examine the mental health of patients with early-stage CKD to prevent suicide.</p> Graphical abstract <p></p>