Abstract In the present paper the results of the studies on the autoacceleration in polymerisation of ethyl and n‐propyl acrylate are reported. The merits and demerits of both mechanisms proposed by BURNETT and DUNCAN have been critically discussed and the results have been interpreted, following BURNETT et al. It has been observed that the critical degree of conversion where the autoacceleration starts, increases with the decrease of the initiator concentration; for any particular concentration of the initiator it is higher for n‐propyl acrylate than for ethyl acrylate.