The article discusses the model of the spread of cremation in the East Lithuanian barrow culture based on the data of radiocarbon dating. It proposes a review of the model established in literature that a wave of cremation spread from the south of the region to the north between the late 4th century AD and of the early 6th century AD. The stage of the earliest cremations can be dated to 248–335 cal AD, and the stage of the latest inhumations to 420–556 cal AD. This suggests that both inhumation and cremation were practised in Eastern Lithuania for about two centuries from the Late Roman period to the Late Migration period. The hypothesis that the practice of cremation spread from south to north is being corrected rather than refuted. While this process was quite sudden, it was due to the spread of a new tradition alongside the old rather than a wave of change regarding burial rites. Cremation spread early (c. 250–400 cal AD) in the northern part of the region and was an established practice alongside inhumation. The practice of cremation probably became prevalent earlier in Southeastern Lithuania. These processes are synchronous with the emergence of the horizon of the burials of chieftains and warriors in Eastern Lithuania, but the determination of an earlier date for this horizon provides grounds for new discussions about its historical, cultural, and social background.