FDG-Positron emission tomography (FDG-PET) is an imaging modality using the physiological tracer glucose [modified as 18-fluorine-2-fluorodeoxyglucose (FDG)], whose uptake and metabolism is increased in malignant cells. While exact tumor staging in lymphomatous diseases is the basis for choosing the appropriate treatment strategy, the detection of nodal and extranodal manifestations are a key prerequisite. This study demonstrates that FDG-PET is an efficient, non-invasive method for the staging of primary untreated Hodgkin's lymphoma (HD) and non-Hodgkin's lymphoma (NHL). Clinical PET scanning is very useful in staging lymphoma patients and is more accurate than computed tomography (CT) in detecting lesions.