Positron emission tomography (PET) with fluorine-18 labeled deoxyglucose (FDG) is useful in the management of lymphomas. In this review, some general concepts of this metabolic test are defined. It has an excellent diagnostic yield in Hodgkin disease as well as in most non Hodgkin lymphomas. Staging, restaging residual mass evaluation and the control of therapy are the main indications for FDG-PET. Images with FDG have a high diagnostic and prognostic value, that is superior to anatomical images and conventional staging techniques. They are also helpful for the assessment of tumor activity in abnormal lymph nodes or large masses that have been treated and reduce their size slowly or show an incomplete resolution. Currently, the resolution of dedicated PET equipments is 6 mm and bigger lesions can easily be detected. The main differences and advantages of FDG versus gallium-67 in lymphoma are also discussed, as well as the initial local experience with the technique in lymphoma patients