The peak expiratory flow rate was determined using the Wright peak flow meter in normal Ethiopian children and adults residing in Addis Ababa (altitude 2500 m). The sample studied was of 84 boys, 69 girls (4-17 years) and 177 men, 148 women (18-70 years). Normality was determined by history alone. Linear multiple regression analysis was used to construct prediction equations that depended upon height and age. The results serve as reference values specifically for Ethiopians residing at altitude. Comparison of the PEFR values determined in 47 Caucasians (22 males, 27 females) working in Addis Ababa, with those from a group of Ethiopians matched for age and height indicated that the mean PEFR was significantly greater in the Caucasians by 7.3% in males and by 8.2% in females.