The paper presents the results of determinations of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in 24 samples of bottom sediments collected in six gauging cross-sections along the course of the Mała Wełna river (western Poland). The samples were collected once a month from May to August 2006. The determinations were made separately in the following granulometric fractions: >2.0, 2.0-1.0, 1.0-0.5, 0.5-0.25, 0.25-0.1, 0.1-0.063, and <0.063 mm, using 3M HCl as the extraction agent. The concentrations of the heavy metals studied were lowest in the 0.5-0.25 and 0.25-0.1 mm fractions, and the highest in the 0.1-0.063 and <0.063 mm fractions, and also in the larger fraction. The determinations were made using atomic absorption spectrometry with flame atomization (F-AAS).