Background: Decreased hemoglobin is a manifestation of chronic kidney disease (CKD), and people who reside at high altitude adapt to hypoxia by increasing their hemoglobin. The study's objective was to determine the influence of altitude and the associated factors on the hemoglobin levels of patients with CKD who were not on dialysis (ND). Methods: This exploratory and cross-sectional study was carried out in three Peruvian cities, located at different altitudes: (1) "sea level" (161 m), (2) "moderate altitude" (2,335 m), and "high altitude" (3,399 m). The study included female and male individuals between 20 and 90 years old, with CKD stage 3a, through stage 5. Results: Of the 256 volunteers evaluated, 92 lived at sea level, 82 at moderate altitude, and 82 at high altitude. The three groups were similar in age, number of volunteers in each CKD stage, systolic blood pressure, and diastolic blood pressure. Hemoglobin levels were statistically different according to gender (p = 0.024), CKD stage, and altitude (p < 0.001). High-altitude dwellers had higher hemoglobin by 2.5 g/dl (95% confidence interval: 1.8-3.1, p < 0.001) than those living at lower altitudes (adjusted for gender, age, nutritional status, and smoking habit). For all CKD stages, the high-altitude population had higher hemoglobin levels than population at moderate altitude and at sea level. Conclusion: Subjects living at high altitude with CKD stages 3 to 5 who are yet ND have higher hemoglobin levels than those who live at moderate altitude and at sea level.