A detailed molluscan succession from Holocene calcareous tufa deposits at the Kotyz Ridge and in the Cisa?ska Gorge in the Czech Karst provides the most complete record from central Bohemia. The succession has been reconstructed from three profiles and chronology provided by AMS radiocarbon dating of charcoal and dating of carbonate by the U-series method. The early Holocene malacofaunas represented by occurrences of index species Discus ruderatus, accompanied by other boreo-montane elements (Vertigo substriata, Vertigo alpestris, Perpolita petronella), dominate in the earliest phases of tufa formation that is dated by the U-series method to 9460±1200 years BP and 5920±1520 years BP in the Cisa?ska Gorge, or before the interval 5070–4800 years BC at the Kotyz Ridge. The change in composition of molluscan assemblages follows in the form of total replacement to Holocene Climatic Optimum (Atlantic, Epiatlantic) malacofaunas, consisting of several indicative elements (e.g. Bulgarica cana, Truncatellina claustralis), which are extinct or relatively rare in that region today, and even in the Czech Republic as well. The youngest phases of molluscan successions are represented by the accession of modern immigrants Xerolenta obvia and Oxychilus cellarius, never documented before from the Subboreal period in this region.