Aims The aim was to examine whether specific skills required for cognitive behavioural therapy (CBT) could be taught using a computerised training paradigm with people who have intellectual disabilities (IDs). Training aimed to improve: a) ability to link pairs of situations and mediating beliefs to emotions, and b) ability to link pairs of situations and emotions to mediating beliefs. Method Using a single-blind mixed experimental design, sixty-five participants with IDs were randomised to receive either computerised training or an attention-control condition. Cognitive mediation skills were assessed before and after training. Results Participants who received training were significantly better at selecting appropriate emotions within situation–beliefs pairs, controlling for baseline scores and IQ. Despite significant improvements in the ability of those who received training to correctly select intermediating beliefs for situation-feelings pairings, no between-group differences were observed at post-test. Conclusions The findings indicated that computerised training led to a significant improvement in some aspects of cognitive mediation for people with IDs, but whether this has a positive effect upon outcome from therapy is yet to be established.