The present study established the reference values and sex differences in the erythrocytic and serum biochemistry parameters of domestic adult quails (Coturnix coturnix). Ninety five adult birds, comprising of 42 males and 53 female Japanese quails were sampled using a simple random sampling technique. Standard procedures were carried out in all haematology and serum biochemistry determinations. The overall mean for the erythrocytic and serum biochemistry parameters were as follows: packed cell volume (PCV) 43.11%, red blood cell count (RBC) 4.31 × 10 6 /µl, haemoglobin concentration (Hbc) 16.21 g/dl, mean corpuscular volume (MCV) 100.69 fl, mean corpuscular haemoglobin (MCH) 39.17 pg, mean corpuscular haemoglobin concentration (MCHC) 39.35 g/dl, aspartate aminotransferase (AST) 59.99 IU/L, alanine aminotransferase (ALT) 20.85 IU/L, alkaline phosphatase (ALP) 107.54 IU/L, total proteins (TP) 5.19 g/dl, albumin (ALB) 3.25 g/dl, globulin (GLB) 1.94 g/dl, albumin: globulin 1.73, total cholesterol (TCHOL) 146.69 mg/dl, total bilirubin (TBIL) 2.37 mg/dl, uric acid (UA) 16.02 mg/dl and creatinine (CREAT) 0.44 mg/dl. The PCV of the males were significantly higher than that of the females, while the MCH and MCHC of the females were significantly higher than those of the males. The serum total proteins, albumin, globulin, uric acid, creatinine, and total cholesterol values of the female quails were higher than those of the male quails. The present data might be useful to avian specialists and veterinary clinicians, but more research works should be carried out on quails to increase the information data base, especially in the tropics.