Hematological parameters were measured in 408 blood samples collected over a 30-mo period from 254 captive mountain gazelles (Gazella gazella) in Saudi Arabia. We evaluated the influence of sex, age, capture method, and season, on these parameters. Evaluations also were made with a small number of anesthetized animals. Males had a significantly higher mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) than females. There was no observed neutrophil: lymphocyte ratio shift for either sex during the first months of life. The effects of different capture methods generally were similar in males and females and included a significantly lower MCV and MCH after quick capture. Animals undergoing slow capture had a significantly lower mean corpuscular hemoglobin concentration (MCHC), and very pronounced stress neutrophilia. We propose that this stress neutrophilia caused the permanently high neutrophil : lymphocyte ratio (62:36 average for all gazelles tested) and the lack of a neutrophil: lymphocyte shift in young animals. Erythrocyte counts were significantly higher in summer, while packed cell volume and hemoglobin concentration were the same in summer and winter; thus there was a significantly lower MCV and MCH, and a significantly higher MCHC in summer in both sexes. Fibrinogen varied significantly by sex, age, capture method, and anesthesia.