{Reference Type}: Case Reports {Title}: Infected pulmonary hydatid cyst: A challenging diagnosis. {Author}: AlRashed FM;AlShahrani DA; {Journal}: Saudi Med J {Volume}: 45 {Issue}: 4 {Year}: 2024 Apr {Factor}: 1.422 {DOI}: 10.15537/smj.2024.45.4.20230078 {Abstract}: Echinococcosis is a parasitic infection that is distributed worldwide. Its clinical presentation depends on the size and location of the cyst. A 7-year-old was found with a superimposed infected pulmonary hydatid cyst that was initially misdiagnosed as complicated pneumonia. Our case underscores the challenges of diagnosing and managing echinococcosis, emphasizes the need for a high index of suspicion, and describes the disease's ability to mimic other clinical entities.