This paper provides an overview of hydromorphological and related classifications of rivers in Slovenia and elsewhere. The Rosgen classification is presented in greater detail; it was used in the study as the basis for developing the first Slovenian hydromorphological classification. A hydromorphological survey form was designed to classify rivers and used in the office and field survey of hydromorphological variables in the 95 river sections selected in Slovenia. In the river sections studied, hydromorphological types were identified by analyzing the co-occurrence of selected hydromorphological variables. This method was used to identify 10 hydromorphological types, for which the main hydromorphological features are presented in this paper. Based on the results of the first hydromorphological classification of Slovenian rivers, guidelines are provided for future work.