Colo-rectal cancer is the most common malignancy of the gastrointestinal tract and is the third frequency for malignancy in humans. CT and MRI development allows an early diagnosis and a modulation of the therapeutic approach. Many papers seem to confirm the role of PET/CT and virtual colonography in the evaluation of primary lesions. The PET/CT appears mode accurate in assessing lymph node metastases. Today, new approaches such as virtual colonoscopy and PET/CT open new horizons in the diagnosis and staging of cancer of the colon and rectum.