The aim of the study was to determine the normal range of some physiological, haematological and serum biochemical parameters and how these vary with sex, age and location under tropical savannah conditions in Northwestern Nigerian donkeys. The study was conducted by taking vital signs and blood samples from 125 donkeys across three states in Northwestern Nigeria. The donkeys were grouped according to their locations, sex and age. The physiological, haematological and serum biochemical profiles obtained from donkeys reared in Northwestern Nigerian were consistent with previous reports and within the recommended reference range established in some tropical countries across the world. There was a significant difference (P < 0.05) in respiratory rate between male and female donkeys, with female donkeys having the higher value (26.70 breaths/minute) than male (25.77 breaths/minute). Significant difference (P < 0.05) also existed in rectal temperature, respiratory rate and pulse rate among different age groups. Younger donkeys had the highest values of 37.85oC, 27.39 breaths/minute and 56.95 beats/minute for rectal temperature, respiratory rate and pulse rate respectively, compared to 37.61 oC, 25.84 breaths/minute and 48.36 beats/minute in adult donkey and 37.51 oC, 25.50 breaths/minute and 48.86 beat/minute in old donkeys. Location also had effect on rectal temperature and pulse rate of donkeys. Zamfara donkeys had significantly higher rectal temperature value (37.73 oC) than Jigawa (37.68 oC) and Katsina (37.55 oC) donkeys, while Katsina donkeys had higher respiratory rate (53.66 breaths/minute) than Jigawa (50.51 breaths/minute) and Zamfara (49.29 breaths/minute) donkeys. There were significant differences (P < 0.05) between male and female donkeys in the counts of neutrophils, lymphocytes and eosinophils. Packed cell volume, hemoglobin, with e blood cells (WBC), neutrophils,