Anemia is a widespread and severe complication of Chronic Kidney Disease (CKD) that significantly accelerates cardiovascular morbidity and reduces the quality of life. This study aims to evaluate the prevalence of anemia and specific laboratory alterations in patients with varying stages of CKD. A retrospective, cross-sectional study was conducted involving 90 patients with CKD stages 3 to 5 and a control group of 30 healthy individuals. Comprehensive laboratory analyses, including complete blood counts, iron profiles (ferritin, transferrin saturation), and estimated glomerular filtration rate (eGFR), were performed. Statistical evaluation utilized the Student’s t-test and chi-square test. The results demonstrated a clear inverse correlation between renal function and hemoglobin levels. Anemia was present in 45% of Stage 3, 78% of Stage 4, and 95% of Stage 5 CKD patients. Hemoglobin levels significantly decreased from 135 ± 12 g/L in the control group to 88 ± 8.5 g/L in Stage 5 CKD patients (p < 0.001). Furthermore, functional iron deficiency, characterized by normal or elevated ferritin (315 ± 42 mcg/L) but low transferrin saturation (18 ± 3%), was observed in 62% of the advanced CKD cohort. The study concludes that anemia in CKD is multifactorial, driven not only by erythropoietin deficiency but also by impaired iron metabolism and systemic inflammation. Early laboratory screening and targeted therapeutic interventions are critical to managing this complication and preventing adverse cardiovascular outcomes.