Natural mortality (M) of Dissostichus eleginoides was calculated after Sparre (1989) from the data obtained during the Chilean longline fishery in Subarea 48.3 (N = 7 848. The von Bertalanffy growth parameters obtained independently by three authors were used. Three cases were considered: fishing site, fishing depth and hook type. It was determined that there were no significant differences in M estimated by fishing depth and hook type with different growth parameters although there were differences in M between fishing sites. On the other hand, when comparing various mean values of M for the different cases, it was found that there were significant differences between fishing sites and between curve hooks No. 14 and straight hooks No. 22. The general mean value of M calculated for the 44 analysed situations was 0.14 ± 0.03.