Pneumocystis carinii pneumonia is rarely encountered in the normal, healthy child. However, children who are receiving immunosuppressive treatment for malignancies or organ transplants, or those who have a congenital immunodeficiency disease are at high risk for contracting this serious and often fatal infection. In this article, pneumocystis carinii pathology will be examined, with emphasis on how it presents in the immunosuppressed child. Diagnostic procedures and treatment of the infection will also be discussed. Finally, nursing implications in caring for the child with pneumocystis will be explored.