OBJECTIVE To assess the effect of stunting on peak expiratory flow rates (PEFR) in Malawian children. METHODS Cross sectional study. METHODS Two public primary schools randomly selected in Blantyre, the largest city in Malawi. METHODS 266 boys and 273 girls aged six to 14 years. METHODS PEFR, height, weight and age of children were determined using standard techniques. Nutritional status of children was assessed using WHO/NCHS height for age, weight for age and weight for height reference standards. RESULTS The data of PEFR were analysed by regression on age and stature. One hundred children (18.6%) were classified as stunted. None of them was under weight or wasted. The equations for prediction of PEFR were calculated separately for stunted and non-stunted children. Stature was a significant predictor of PEFR values in both groups of children. The differences between stunted and non-stunted children of both sexes in slopes and intercepts of the regression lines of PEFR on stature were non-significant. Stunted children of both sexes had significantly lower PEFR than their counterparts with normal height for age index. CONCLUSIONS Stunting in Malawian children aged six to 14 years is associated with decreased rate of development of PEFR in proportion to linear growth retardation. Prediction equations calculated for children with normal height for age index can be used for assessment of PEFR in stunted children.