Hodgkin‘s Disease (HD) is one of the malignant diseases with good chances for a cure. The prognosis for cure depends on the initial stages and the outcome after initial treatment. Stages I or II at diagnosis, or a complete remission after initial treatment are good indicators for the best prognosis to patients. A frequent problem faced by clinicians is met at the post-therapy stage because of the difficulty of distinguishing between dead tissue and disease activity in residual masses. Considering that these two situations include therapy options that run from treatment abstention to autologous stem cell transplantation, it is extremely important to distinguish them accurately. Classical Tomography Scan (CT Scan), Gallium scintigraphy, Magnetic Resonance Imaging (MRI) or Positron Emission Tomography (PET) are used to investigate residual masses. In order to clarify the best way to confirm the post-treatment status of patients affected by HD, we describe in this paper our experience of using PET to solve those problem situations where a CT Scan or MRI were not conclusive and Gallium was negative.