Maximal expiratory pressure (MEP) can be used as an index of respiratory muscle strength and of the ability of an individual to cough effectively. The influence of anthropometry, nutritional status and ethnicity on MEP was studied in 113 young healthy Indian males and 53 Tibetans between 18 and 30 years of age. All subjects underwent an anthropometric assessment. Anthropometric variables (BMI, log BMI) explained only 12.5% of the variance in MEP. MEP was significantly lower in chronically undernourished subjects when compared with anthropometrically similar underweight subjects (P < 0.05). The Indian subjects had significantly lower MEP's than BMI matched Tibetan subjects (P < 0.01). This difference may have been due to the higher chest circumferences in the Tibetans (P < 0.01). While general muscle strength (maximal hand grip) and MEP were significantly correlated (r = 0.26, P < 0.01), the strength of the correlation was relatively low, suggesting that the determinants of the two measures were considerably different.