The purpose of this study was to investigate the influence of batch size during scale-up on the abrasion of biconvex tablets. Labelled tracer tablets of six different crushing forces (23-116 N) were mixed at different times and peripheral speeds in a laboratory (4 kg) and production (360 kg) perforated pan coater. The weight loss of these tracer tablets was determined. The main factor affecting the abrasion in both scales is the tablet crushing force as a nonlinear decrease in the abrasion was observed with increasing crushing force of the tablets. An increase in mixing time results in an increase in abrasion for the laboratory scale. In contrast to the production scale an influence of the peripheral speed on the abrasion could not be observed in laboratory scale. There is no difference in total abrasion for the laboratory scale and production scale for low peripheral speed. At higher peripheral speeds the abrasion in the production scale is slightly higher than in the laboratory scale.