OBJECTIVE To develop and evaluate a computer program for interpretation of spirometry. METHODS The spirometry programme was constructed in Epi Info software using a previously defined algorithm for interpretation. The programme incorporated current American Thoracic Society guidelines on interpretation of spirometry and was based on regression equations for healthy North Indians previously derived by us. The programme was pretested for two months before being put to routine use. RESULTS Use of this spirometry programme led to consistent interpretation of spirometry results. There was significant saving of time while preparing reports, without any additional expenditure. CONCLUSIONS The use of such computer programmes accelerate the reporting of pulmonary function test results at little extra cost, and all interpretations are performed in a consistent fashion.