Factors determining the distribution of highly endangered marsh dandelion species in Polish and Estonian coastal grasslands have been investigated. The aim of this study was twofold: (i) to determine which environmental variables are responsible for the vegetation patterns in coastal grasslands with marsh dandelion and (ii) to analyse the ecological spectra of the identified marsh dandelion species. Altogether 51 plots were sampled (in 2013 and 2014). They were used following statistical analysis: DCA, CCA, Spearman's rank correlation test, Kruskal-Wallis test and hierarchical divisive cluster analysis (TWINSPAN). In total, three marsh dandelion species were found in Polish and Estonian coastal grasslands. The only species found in Poland was Taraxacum balticum. In Estonia all three species occur: T. balticum, T. decolorans and T. suecicum. Taraxacum balticum has been found in the widest ranges of all soil properties included, usually on organic, saline, non-carbonate and acid to slightly acid substrate. Taraxacum suecicum and T. decolorans have been found only on mineral, non-saline and slightly alkaline to alkaline substrate. The ecological spectra determined for endangered marsh dandelion species can be used to improve the methods of their protection. Nomenclature: mosses - Ochyra et al. (2003); vascular plants - Mirek et al. (2002).