This article focuses on the Early–Middle Bronze Age (MBA) transition in Sicily and southern Italy from a Bayesian radiocarbon perspective. The aims are to: (i) estimate the beginning of the MBA (i.e. Thapsos–Milazzese culture in Sicily; Apennine culture in southern Italy) at four key-sites; (ii) assess the existence of a site-wide variability; and (iii) understand if an offset is likely to have existed between the beginning of the MBA and the Aegean Late Helladic (LH) IIIA phase, which currently marks the start of the MBA. The study indicates that the MBA probably started earlier at Portella (95.4% range 1541–1430, mode 1465 BC) and Roca Vecchia (1706–1394, mode 1460 BC) than at Coppa Nevigata (1527–1292, mode 1410 BC; or 1490–1265, mode 1380 BC) and Ustica (1609–1261, mode 1405 BC). Also, the beginning of the MBA at Portella and Roca Vecchia is probably earlier than that of the LH IIIA. This suggests that the current synchronization between MBA and LH IIIA, based on historical grounds, needs revision as radiocarbon evidence points to an earlier start of the MBA at two of the four sites. Overall, by means of scientific dating methods and Bayesian modelling, the study allows us to set in a different perspective the chronology proposed in the current literature based on historical synchronizations. Copyright © 2013 John Wiley & Sons, Ltd.