Community-acquired bacterial pneumonia is a common and important disease which is associated with significant morbidity and mortality worldwide. Various pathogens cause the disease, but often the underlying pathogen is not identified. Early diagnosis is key to successful therapy; however, frequently the disease is misdiagnosed. In this white paper Maxim Kosov, PSI CRO AG (USA), John Riefler, PSI CRO AG (USA), Maxim Belotserkovskiy, at PSI CRO AG. discusses why close cooperation between investigative sites and medical monitors of sponsor/CRO is essential.