Background: Knowledge of discourse abilities of adults with intellectual disability (ID) and mental illness is limited. The present study examined the procedural discourse skills of two cohorts of adults with ID--one cohort with (n = 7) and one cohort without (n = 7) a psychiatric diagnosis of psychosis. Methods: Participants completed the "dice game", a procedural discourse elicitation procedure that has been used by previous researchers. Results: Results revealed that while all participants demonstrated an understanding of the task, participants with ID alone were more able to communicate the key elements of the game than the participants in the dual diagnosis group. Conclusions: Results of this investigation suggest that individuals with dual diagnosis have difficulties that may relate to previously identified discourse impairments in people with schizophrenia, and this may relate to a larger difficulty in taking into account the listener's needs.