This paper is a review of 29 cases of mediastinal tumors originating in the mediastinum or metastasized from other organs and classified on the basis of histopathological types and specific anatomic location in this depart-ment, during nine years period from January 1959 to December 1967. In twenty-three cases, diagnosis was confirmed by histological findings and the rest of the cases were considered to be mediastinal tumors by clinical and/or roentgenological findings. In this series, metastatic mediastinal carcinomas of unknown primary site were most frequent [30.4%] and lymphoma ranked second in frequency comprising 21.7% of total. Range of age was 5 to 61 years and average mean age was 39 years old. Sex ratio was 1.4 male to female. Subjective complaints in order of frequency were as follows: dyspnea [37%], cough [34%], chest pain[24%] and chest discomfort [21%]. Objective signs were as follows: hoarseness [17%], palpable cervical lymph node[17%], blood tinged sputum [10%], weight loss [10%] and superior vena cava syndrome [7%]. There was no operative mortality. There were histologically nine different kinds of mediasfinal tumors in this series.[KTCS 1968;1:37-44]