One hundred pediatric patients with community acquired acute lower respiratory tract Infections (ARI) were studied to evaluate the efficacy of some rapid specific and nonspecific diagnostic tests to define their etiology and sub sequent treatment. The Indirect Immunofluorescence test detected respiratory syncitial virus In 43.95% of the cases, and the latex agglutination in urine, in a select group of patients, detected capsular antigen for H. influenzae and pneumococcus, 12.9% and 13.3% respectively. ln the group of nonspecific tests two or more positive acute phase reactants correlated with bacterial etiology rather than with viral Infection. Cold agglutinins did not show sensitivity for detection of M. pneumonlae Infections. The use of rapid test such as Indirect Immunofluorescence for the diagnosis of respiratory syncitial virus is recommended In the Initial study of ARI. Rapid nonspecific test such as acute phase reactants are useful in predicting viral or bacterial etiology.