Modelling of microstructure evolution during hot rolling of plate and long product of 316L stainless steel has been investigated in the present work. A prediction of microstructure evolution during full scale industrial hot rolling of both plate and bar has been carried out by utilizing the MICDEL model. It has been noted that a correct prediction of strain and strain rate are critical for predicting the recrystallization behaviour of steels during bar rolling. A good relationship has been obtained between the full scale results of austenite grain size predicted by MICDEL and those determined metallographically. © 2008 Verlag Stahleisen GmbH, Düsseldorf.