To determine normal values of respiratory function for Sudanese, a randomized stratified cross-sectional study was performed on 2250 healthy Sudanese aged 7-86 years in 2002-05. Data were obtained through a questionnaire, pulmonary function testing and taking anthropometric measurements. Lung function and anthropometric measurements were correlated and regression equations were derived. Sudanese of Arab ethnic background had significantly higher forced vital capacity (FVC), forced expiratory volume in 1 (first) second (FEVI) and peak expiratory flow rate (PEFR) than those of African ethnicity. In adults a positive correlation was found between lung function and height and a negative correlation with age. Gender and ethnic variations in Sudanese lung function were confirmed. Comparisons were made with data from other international studies. These values can be used as reference values in respiratory clinics in Sudan.