In this paper, we document the results of retrospective analysis of length frequency data collected during a trawl survey in Brunei Darussalam from July 1989 to June 1990. The study forms part of concerted efforts under the TrawlBase Project to provide enhanced historical baselines for fisheries management in developing Asian countries, in general, and Brunei Darussalam in particular. The specific objectives of this study were to assess the exploitation level of the demersal fish stocks (during the 1989–1990 period), derive reference points and baselines for current management efforts, and obtain parameters for subsequent (multispecies, ecosystem) studies of fisheries in Brunei Darussalam.