community acquired pneumonia is one of the main health problems in children. s. pneumoniae is the most important bacterial microorganism at any age. gram negative bacteria are a rare cause of this entity and when present, they usually are related with several risk factors like immunocompromised host, prolonged hospitalization and antimicrobial therapy, repeated surgical interventions, prolonged use of invasive mechanical ventilation and other medical invasive devices. in this group of bacteria, pseudomonas aeruginosa is the third in order of frequency to cause pneumonia and sepsis in the community setting. it's more widely known as a nosocomial agent. it's very unusual to be community acquired and even rarer in patients without risk factors for infection by this pathogen. in this paper we describe the case of a girl with both community acquired pneumococcal and pseudomonas necrotizing pneumonia and empyema at the same time, without any evidence of a predisposing factor.