To document the normal values of pulmonary function tests in children and changes occurring in their values with various respiratory disorders, a study was carried over a period of one year in 95 healthy controls (39 females and 56 males) of 8-13 years of age and 51 cases with respiratory disorders (bronchial asthma-31, pneumonia-10, empyema-10) of matched age, sex and height distribution. The lung functions studied were FVC, FEV1, FEV1/FVC, PEFR and FEF25-75%. In children with bronchial asthma, the FEV1/FVC%, PEFR and FEF25-75% were reduced in accordance with the severity of the disease. A typical restrictive pattern of equivalent decrease in FVC and FEV1 along with insignificant lowering of flow rates, i.e., PEFR and FEF25-75% was observed in pneumonia whereas in patients of empyema a combined pattern of significantly decreased FVC and FEV1 along with mildly reduced FEV1/FVC%, PEFR and FEF 25 75% was observed.