The Shanghai study examined a five-year cohort of adult patients with MASLD (metabolic dysfunction-associated steatotic liver disease) from Pudong County. A higher creatinine clearance rate (CCR) was independently associated with a reduced risk of cardiovascular mortality (HR = 0.95; 95% CI: 0.95–0.96) and all-cause mortality (HR = 0.97; 95% CI: 0.96–0.97), both P < 0.001. Compared with the lowest tertile (T1), the middle (T2) and the highest tertile (T3) had lower risks (P for trend < 0.05). RCS analysis showed a non-linear correlation for both outcomes (P for non-linearity < 0.05) and Kaplan-Meier curves confirmed a higher probability of survival at T3 (log-rank P < 0.001). LASSO regression selected CCR into the prognostic model, which ROC analysis confirmed as useful for risk stratification. Sensitivity analyzes confirmed the stability of the findings. CCR serves as a valuable prognostic marker of renal function in patients with MASLD.