Pneumocystis jiroveci is still a dangerous pathogen. The child with extreme immaturity has gone through severe circulatory and respiratory failure after birth, a few episodes of infection including the central nervous system, and has gone through a lot of invasive procedures like intubation, long-term central catheters and parenteral nutrition. Inclusion of trimethoprim and sulfamethoxazole targeted therapy resulted in clinical improvement and gradual resolution of inflammatory changes.