The present paper deals with the presentation of a new approach in sediment quality estimation. This approach studies the ranking toward ecotoxicity of lake sediment samples from Turawa Lake in Poland with respect to chemical pollutants such as polychlorinated biphenyls (PCBs), pesticides, polyaromatic hydrocarbons (PAH) and heavy metals. The sediment quality estimation is done by combining Hasse diagram technique (HDT) with self-organized maps (SOM). The classification abilities of SOM are used as preprocessing procedure of the initial data matrix before applying HDT. The Hasse diagram analysis shows two specific sediment pollution ‘patterns’. The Hasse diagram structure is discussed in relation to the environmental management of Turawa Lake region. Copyright © 2011 John Wiley & Sons, Ltd.