Carcinoma of unknown primary location are heterogeneous group of metastatic tumours where primary location could not be discovered with detail anamnesis, clinical examination and diagnostic procedures. Patients with metastasis carcinoma of unknown primary location in clinical oncology are represent with about 4% of total number of patients with solid tumours. The most frequent location carcinoma of unknown primary location, discovered with autopsy, are lungs, pancreas, colon, kidney, prostate and breast. Metastasis in cervical lymph nodes carcinoma of unknown primary location are represent between 3-9% of total number of patients with head and neck carcinoma. Patients with persistent cervical lymph node should be examined through diagnostical plan "step by step" for identification carcinoma of unknown primary location.