Morphological variation of Carex muricata from 232 localities in the Czech Republicwas analysed. The plants were preliminarily classified using qualitative characters into six species: C. contigua, C. muricata, C. pairae, C. chabertii, C. divulsa, and C. leersiana. Of 27 quantitative characters, all were used in a principal components analysis and 25 in a discriminant analysis. Both analyses were done using the data for all the species and then separately for the taxonomically complicated species pairs. In the discriminant analysis, the most useful characters for separating particular species were selected; they included the distance between the first and second lowermost spike of the infructescence, infructescence length, glume length in pistillate flower, achene length, length of perigynium beak and spike size. In the classification discriminant analysis, with the six most important characters, 94.4% of plants were correctly classified to the designated groups. The analysis showed that some species pairs (C. muricata – C. pairae, C. chabertii – C. leersiana) are only partially distinguished by quantitative morphological characters. Some other species (C. contigua, C. divulsa), however, are well differentiated and easily identified.