For the last three years, CCAMLR's Working Group on Fish Stock Assessment (WG-FSA) has accorded high priority to the development of methods of integrating different indicators of stock status into assessments using the Generalised Yield Model (GYM). In this paper, we propose a method, based on the use of importance sampling, for incorporating information on trends in standardised CPUEs into GYM assessments. The use of the method is illustrated using data for Patagonian toothfish (Dissostichus eleginoides) in Subarea 48.3. The method requires only very small adjustments to the computer program implementing the GYM assessments.