Research into product costing practice has not studied whether there are differences in product costing practice between different types of manufacturing. This paper compares the product costing practices of operating units in discrete-part and assembly manufacturing, and continuous production process manufacturing. The results show that there are few differences in product costing practices between these two manufacturing methods. Similar proportions of operating units in these two manufacturing environments use similar methods to treat overheads and have similar experiences of activity-based costing. The only area of difference is in the use of overhead rates where significantly more units in discrete-part and assembly manufacturing use a direct labour hour rate and significantly more units in continuous production process manufacturing use units produced and production time-based rates.