Background: Chronic kidney disease (CKD) is a growing global health issue characterized by persistent structural or functional kidney impairment lasting more than three months, and is associated with significant morbidity and mortality. Identifying local causes and staging patterns is essential for improving prevention strategies and optimizing healthcare resources in tertiary care settings. Objective: This study aimed to evaluate the clinical characteristics, staging distribution, and etiological profile of CKD patients attending a major public tertiary hospital in Nepal. Methods: A hospital-based descriptive cross-sectional study was conducted in the Department of Nephrology at Bir Hospital, Kathmandu, Nepal, from June 2025 to May 2026. A total of 202 adult patients (≥18 years) diagnosed with CKD were enrolled using convenience non-probability sampling. Data on demographic characteristics, medical history, and disease staging were collected through a structured proforma, patient interviews and review of electronic medical records. Results: Among the 202 patients included, the majority were male (60%, n=121) and over 60 years of age (50%, n=102). Diabetic nephropathy was the most common underlying cause, accounting for 50% (n=102) of cases, followed by hypertensive nephropathy (20%, n=40), chronic glomerulonephritis (15%, n=30), and obstructive uropathy (10%, n=20). Polycystic kidney disease and systemic lupus erythematosus each accounted for 2% (n=4), while 1% (n=2) had CKD of unknown origin. Regarding disease duration, 75% (n=152) had CKD for more than five years. Half of the patients (50%, n=102) were classified as Stage 5, while 25% (n=50) were in Stage 2, 10% (n=20) in Stage 3, 10% (n=20) in Stage 4, and 5% (n=10) in Stage 1. Conclusion: Diabetic and hypertensive kidney disease are the leading causes of CKD in this tertiary care setting, reflecting a shift toward non-communicable metabolic disorders. The large proportion of advanced-stage diagnoses suggests need of improvement in detection practices as well as the long duration of the need for strengthened primary care screening, early management of diabetes and hypertension, and broader public health interventions to prevent progression to advanced kidney disease.