Historical and current occurrence of the obligate halophyte Pholiurus pannonicus was studied in Slovakia during the period 2003-2009. The species had been occurring in the Podunajská nížina Lowland and the Východoslovenská nížina Lowland; 30 localities were found in total. Recently the number of localities has decreased markedly and the species was confirmed only in the Podunajská nížina Lowland. We documented only seven localities during the study. Therefore, we confirmed that Pholiurus pannonicus belongs to the critically endangered plants of Slovak flora.