The association between P.E.M. and frequent and severe life threatening infections including lower respiratory tract infections have been always reported. Lack of the usual general and local signs of infection in P.E.M. makes the diagnosis difficult and sometimes only postmortem. This study evaluated the frequency of chest infections as well as the sensitivity, specificity and predictivity of different signs and symptoms of the disease in 100 children with severe P.E.M. (marasmus, kwashiorkor, and marasmic kwashiorkor). Sixty two percent of the studied children had chest infection (33% pneumonia, 29% bronchitis). Although most patients were symptomatic, yet, signs and symptoms were few and mostly non specific. Chest roentgenograms are thus mandatory in evaluating patients with P.E.M. whenever possible. The only valuable signs suggestive of chest infection in P.E.M. were tachypnea (> or = 40/min) and/or chest indrawing. Both were moderately sensitive, highly specific and predictive of the disease particularly pneumonia. Their presence thus, its indicative of the need for early institution of antibiotic therapy even before the results of chest roentgenograms. Total Leucocytic count was of little diagnostic value while contrary to the common belief that tuberculin test is usually negative in P.E.M., the use of double the usual dose of P.P.D. (i.e. 10 TU) yielded positive reaction in some of the studied patients and thus must not be omitted from the routine investigations of malnourished patients.