Our prospective nonrandomized controlled study enrolled 165 children with acute pneumonia (AP) from 2 to 18 years of age, which included 51 (30.9 %) children with ANP. There were 91 (55.2 %) boys and 73 (44.8 %) girls. Dynamic complex determination of BPI and CRP concentrations in blood serum from children with AP was a sensitive indicator to predict the development of complications and ANP. High levels of BPI and CRP in children with AP were prognostic signs for good outcomes of the disease. In the presence of an initially low BPI level (<10 ng/ml) and high CRP (>100 mg/L), disease progression was noted, which included the development of bronchopleural complications.