The family of Bacillariaceae Ehrenberg is a group of well-known raphid diatoms, associated with water quality. Our current knowledge of the species diversity of this group in Turkey is still incomplete. There are three river basins in the Kütahya region in Turkey, located in the eastern part of the country, including the Gediz, Sakarya and Susurluk basins, thus the region is rich in lotic waters. We present each taxon based on our observations of specimens collected in the Kütahya region. A total of 53 sites were surveyed in this study and a total of 65 taxa from Bacillariaceae were identified. Of these 65 taxa, 15 are recognized as the first records for Turkey. For each taxon, we indicate the reference(s) used for its identification. To facilitate the identification by others working on the Turkish freshwater diatom flora, we also present dimensions of the taxa identified, the distribution of each taxon in the Kütahya region, the distribution of each taxon in Turkey as well as one or more figures for each taxon.