Background and aims: Patients with chronic kidney disease (CKD) have high residual risk of cardiovascular events, whether the residual risk is associated with elevated level of lipoprotein(a) [Lp(a)] is unascertained. We aimed to explore the impact of Lp(a) levels on the risk of major adverse clinical events (MACEs) in CKD patients hospitalized for acute coronary syndrome (ACS) compared to those without CKD. \Methods: The data of patients hospitalized for ACS were collected at the China-Japan Friendship Hospital from January 2015 to December 2019. Patients were divided into 2 groups according to renal function: non-CKD group (eGFR >= 60 ml/min/1.73 m(2)) and CKD group (eGFR <60 ml/min/1.73 m(2)). Multivariate Cox regression analysis and restricted cubic splines were performed to explore the relationship between Lp(a) levels and MACEs.Results: A total of 1306 patients were enrolled. Patients with CKD had higher Lp(a) concentrations compared with those without CKD. During a median follow-up of 3.9 years, an elevated Lp(a) value was an independent predictor for MACEs in the overall population. Patients with a high Lp(a) level had higher risk of MACEs than those with a low Lp(a) level, regardless of renal function. The association between higher Lp(a) levels and MACEs remained consistent using the cut-off value of median (11.57 mg/dL), 30 mg/dL and 50 mg/dL in patients with CKD. On the contrary, Lp(a) higher than 50 mg/dL was associated with significantly higher risk of MACEs in patients without CKD. Conclusions: We confirmed that a high Lp(a) level was associated with long term adverse outcomes in ASC patients, especially in those with CKD.