The natural radioactivity levels in soil and sediment samples of Firtina Valley have been determined. To our knowledge, there seems to be no information about radioactivity level in the Firtina Valley soils and sediments so far. For this reason, soil and sediment samples were collected along the Firtina Valley and analysis on the collected samples were carried out to determine U-238, Th-232, K-40 and Cs-137 radioisotopes using high purity germanium detector. The activity concentrations obtained for Ra-226, Ph-214, Bi-214, Ac-228, Tl-208, K-40 and Cs-137 are given in the unit of Bq/kg. The results have been compared with other radioactivity measurements in different country's soils and sediments. The radium equivalent activity (Ra-eq), the absorbed dose rate (D), the external hazard index (H-ex), the annual gonadal dose equivalent (AGDE) and the annual effective dose equivalent (AEDE) were also calculated and compared with the international recommended values. (c) 2007 Elsevier Ltd. All rights reserved.