Randomized controlled trials have established that cognitive behavioural therapy (CBT) is effective in helping people with psychosis, though there is enormous variability in outcome. It is not clear what patient factors contribute to good outcomes. In fact, most studies considering client factors have excluded people with psychosis. It is clinicians who are deciding who is likely to benefit from CBT for psychosis (CBTp), though little is understood in terms of their views on who benefits from CBTp. This study investigated clinicians' views on client characteristics that influence outcome in CBTp. A Q-set of 61 client characteristics was developed from a literature search and interviews with clinicians experienced in working with CBT and/or psychosis. Twenty-one participants (familiar with psychosis and CBT through education, profession, practice or knowledge) rated the items based on their importance in effecting a positive outcome, on a forced normal distribution. 21 completed Q-sorts yielded four factors, named as: acceptance and application of the cognitive model; attending to the present; secure base; meaningful active collaboration. Items regarding therapeutic alliance were highly endorsed throughout all factors. Some empirically-based items were not endorsed, although overall, clinician responses were consistent with prior research.