Background: Tramadol-diclofenac (TD-DF) could be used in chronic pain management. Concurrent use may present renal complications due to their individual nephrotoxic profile. The present study assessed the kidney function and histology of tramadol-diclofenac treated albino rats.Methods: Forty two adult albino rats divided into seven groups A-G were used for this study. Rats were orally administered with TD (12 mg/kg/day), DF (6 mg/kg/day), and TD-DF for 14 days including two recovery groups. Rats were weighed and sacrificed at the termination of drug treatment. Serum was extracted from blood and evaluated for creatinine (Cr), urea (U), uric acid (UA), total protein (TP), albumin (Ab) and serum electrolytes (K+, Na+, Cl-, and HCO3-). Kidneys ...