Recent work in the Casablanca area considerably modified earlier interpretations of its prolific Palaeolithic record. New results reported in this paper stress the absence of traces of a very early human occupation. The main part of the rich Acheulean sequence at casablanca dates from the second part of the Middle Pleistocene, though palaeomagnetic data suggests that the earliest traces of human activities date from before the Brunhes-Matuyama boundary (Thomas-1 quarry, level L). Throughout the Acheulean sequence the same lithic raw materials were used, which allows comparison of technological characteristics of the various assemblages.