In order to evaluate the anatomic extension of neoplastic disease according to the TNM system sufficiently, inclusion of imaging techniques is absolutely necessary. In addition, decisions on further clinical processing are based on precise identification of primary tumor extent (T), condition of regional nodes (N) and possible presence of distant metastases (M). Breast cancer, lung cancer, colorectal cancer and prostate cancer represent the most common tumor entities. Within this context the importance of imaging techniques for diagnosis, prognosis, therapy and follow-up of patients with these malignancies is presented in this report.