The silver staining procedure is commonly used to visualize the activity of ribosomal RNA genes, since it has been established that only those NORs of metaphase chromosomes that are functionally active during the preceding interphase are capable of staining (Galetti et al., 1984; Schmid et al., 2006). Nucleolus organizer regions (NORs) are used as markers to indicate intra- and inter-species chromosomal polymorphism in many groups of fish (Ra´b et al., 2008). There are no available reports specifying the activity of nucleolus organizer regions location in Kura bleak (A. filippii) chromosomes by silver staining. The aim of this paper is to present the chromosome complement, number and location of the nucleolar organizer regions (NORs) of A. filippii (Kessler, 1877), commonly known as Kura bleak from northern Iran, a survey initiated by Gul et al. (2006).