As the first part of a prospective epidemiological study of the lung function and dust exposure of workers at the Rössing Uranium Mine in SWA/Namibia, various measurements of lung function of 1,407 workers were carried out. This was necessary in order to follow up any chronic obstructive pulmonary disease that might develop. The opportunity was used to test existing prediction formulae and to develop formulae for normal values for workers at the Rössing mine.