A comparative bioavailability study was performed using two commercially available types of carbamazepine tablets, by statistical analysis of serum levels and other bioavailability parameters. After single oral dose the extent of absorption from the two preparations was similar, although a statistically significant difference in absorption rates was observed. In a multiple-dose study no significant difference in serum carbamazepine levels was found, so the tablets could be considered as bioequivalent drug products.