The differentiation between a pseudo-pneumoperitoneum and true pneumoperitoneum on an initial chest radiograph is challenging but essential to clinical practice. The former is managed conservatively whereas the latter may require surgical intervention. Chilaiditi's sign describes a rare incidental radiological finding of gas filled bowel interpositioned between the right hemi-diaphragm and the liver, which is visible on a plain abdominal or chest radiograph. It is often misdiagnosed as a pneumoperitoneum. Correct diagnosis of Chilaiditi's sign in an asymptomatic patient can prevent unnecessary procedures. We have reported one incidental chest radiograph with Chilaiditi's sign in a patient presenting and treated for pneumonia. The report aims to illustrate the diagnostic dilemma experienced by clinicians in distinguishing a true versus pseudo-pneumoperitoneum on a chest radiograph.