Aims: This study was conducted to evaluate the effects of pregnancy on the physiological responses in rabbit model in early, mid and late gestation periods. Materials and Methods: The experiment was performed according to the complete randomized design. Fourteen (14) pregnant and non pregnant rabbits, 7 in each group, were used in this study. Pregnancy was ascertained by vaginal swabs taken after copulation by mature fertile male rabbits. Blood and serum constituents' responses were investigated at days 0, 7, 14, 21 and 28 of gestation. Results: The obtained results revealed significant (P 0.05) increase in respiration rate (RR) in mid-gestation and in heart rate (HR) at late gestation. The packed cell volume (PVC), erythrocyte count, haemoglobin concentration (Hb) and total leukocyte count (TLC) were significantly (P 0.05) reduced in mid and late gestation. The serum levels of total protein decreased and cholesterol increased significantly (P 0.05) in early, mid and late gestation. The plasma osmolality decreased significantly (P 0.05) at mid gestation. Cortisol level increased significantly (P 0.05) during mid and late gestation. Conclusions: The study concluded that the pregnancy altered HR, hematological, serum parameters and cortisol level in pregnant rabbit model.