The cross-linking of three different paraffin waxes - a hard oxidized wax, a medium wax, and a hard wax with narrow molar mass distribution - in the presence of dicumyl peroxide (DCP) was investigated thermoanalytically. DSC and TG curves for untreated waxes and waxes treated with different amounts of DCP were obtained and the observations were compared with gel content data obtained through gravimetric analysis. It was found that all three waxes cross-linked in the presence of DCP, with the extent of cross-linking increasing with increasing DCP : wax ratio. It was also clear that the higher melting fractions of the different waxes preferably cross-linked. From the gel content data it seems as if the oxidized and higher molar mass waxes tend to cross-link at a faster rate.