This work was conducted to evaluate the impact of water deprivation on physiological responses, serum hormones, metabolites, electrolytes, haematology and thermoregulatory parameters of Ossimi ewes during summer months. Total of 12 healthy, non-pregnant and non-lactating Ossimi ewes (2-2.5 years of age and average BW of 43.44 ±1.14 kg) were divided into 2 groups, control and ewes exposed to water deprivation cycles 24h, 48h and 72h /week for 3 months. Temperature-humidity index (THI) was calculated. Thermoregulatory response, rectal temperature (RT) and respiration rate (RR) were determined. Serum hormones [aldosterone, thyroid hormones (T3&T4), estradiol (E2), and progesterone (P4)], IgG, total proteins (TP), albumin (Alb), globulin (Glb), triglycerides (TG), cholesterol (Chol), glucose (Glu), creatinine (Creat), urea, Na+, Cl^-, K+, and liver enzymes (ALT, AST) were assayed. Haematological parameters (CBC) in blood were measured. Results showed that RR and RT were higher (P≤0.05) in deprived ewes after 24h, while their values of 48h and 72h were the same as compared to the control. No changes in serum hormones were observed in deprived ewes, except aldosterone level which increased (P≤0.05) in deprived ewes. There were no variations in serum TP, Glob, Creat, urea and liver enzymes (ALT, AST) while Alb, TG, Chol, Na⁺, and Cl^- were elevated (P≤0.05), while  Glu and K⁺ declined (P≤0.05) by water deprivation. Haematological parameters sustained unaffected after deprivation. It is concluded that Ossimi ewes could easily maintained under the conditions of water scarcity or drought without adverse influences.