Diatom samples were collected during July 2010 at 15 localities from different types of substrate (stone surfaces, sand, mud, filamentous algae and submerged mosses) from the Dojkinci River. During the research period, 124 taxa were determined within 43 genera. Among numerous common diatoms we recorded three taxa for the first time in Serbia: Brachysira intermedia (Øst.) Lange-Bertalot, Chamaepinnularia mediocris (Krass.) Lange-Bertalot and Navicula tridentula Krass. Also, we observed 21 taxa which are rarely recorded taxa for Serbia. The most interesting was Diatomella balfouriana Grevill. that was previously known only from the River Tisa near Titel. In the studied material, it was identified only in samples collected from the surface of boulders with mosses at the third locality. Their morphology, distribution and ecology are presented in this paper.