Background and Objectives: This study evaluated the clinical characteristics of the acute coronary syndromes (ACS) in chronic kidney disease (CKD) patients and established prognostic values of the biomarkers and echocardiography. Materials and Methods: 273 patients admitted to the cardiology department of the Clinical County Emergency Hospital of Oradea, Romania, with ACS diagnosis were studied. Two study groups were formed according to the presence of CKD (137 patients with ACS + CKD and 136 with ACS without CKD). Kidney Disease: Improving Global Outcomes (KDIGO) threshold was used to assess the stages of CKD. Results: Data regarding the medical history, laboratory findings, biomarkers, echocardiography, and coronary angiography were analysed for both groups. ACS parameters were represented by ST-segment elevation myocardial infarction (STEMI), which revealed a greater incidence in subjects without CKD (43.88%); non-ST-segment elevation myocardial infarction (NSTEMI), characteristic for the CKD group (28.47%, with statistically significance p = 0.04); unstable angina and myocardial infarction with nonobstructive coronary arteries (MINOCA). Diabetes mellitus, chronic heart failure, previous stroke, and chronic coronary syndrome were more prevalent in the ACS + CKD group (56.93%, p < 0.01; 41.61%, p < 0.01; 18.25%, p < 0.01; 45.26%, p < 0.01). N-terminal pro b-type natriuretic peptide (NT-proBNP) was statistically higher (p < 0.01) in patients with CKD; Killip class 3 was evidenced more frequently in the same group (p < 0.01). Single-vessel coronary artery disease (CAD) was statistically more frequent in the ACS without CKD group (29.41%, p < 0.01) and three-vessel CAD or left main coronary artery disease (LMCA) were found more often in the ACS + CKD group (27.01%, 14.6%). Conclusions: Extension of the CAD in CKD subjects revealed an increased prevalence of the proximal CAD, and the involvement of various coronary arteries is characteristic in these patients. Biomarkers and echocardiographic elements can outline the evolution and outcomes of ACS in CKD patients.