Four charcoal samples from loess key sites in Austria, Moravia, and western Ukraine were submitted to ABOx (acid-base oxidation) pretreatment to compare results with the classical ABA (acid-base-acid) method. For this purpose, char-coal samples already dated in Groningen laboratory were selected from 3 archaeological sites: Molodova V in western Ukraine (subunit 10-1, ~32.6 ka BP), Willendorf II in Austria (unit C4, ~32.1 ka BP and unit C8, ~38.9 ka BP) and Vedrovice V in Moravia (unit 4, upper part of Bohunice soil, ~39.5 ka BP). Each selected charcoal sample has been homogenized and divided into 3 subsamples, which were submitted to ABA in Groningen and to ABA and ABOx pretreatments in Oxford. The results show that the ABOx dates are older than the ABA dates. Nevertheless, down to ~40 ka BP ABOx and Groningen ABA dates appear in good agreement within a time interval of ~1 millennium at 1. However, Groningen ABA pretreatment pro-duces older dates than the Oxford ABA pretreatment. Both Oxford ABOx and Groningen ABA pretreatments provide sets of dates in good agreement with the chronological background of each selected site.