The sequence of prehistoric cultural developments in Nubia has been regarded as one of the best-dated series in North Africa. Eighteen new dates obtained by redating of residuesfrom previously dated samples and the processing of samples held in storage plus a series of recently excavated examples have indicated, however, the need for significant revision of the original chronology. Almost all of the new dates, whether derived from residues or from new samples, were older than the original dates. No adequate explanation is offered for the discrepancies in the two series of dates, although two possible contributing factors are noted. -- AATA