This study used IQ, along with measures of premorbid adjustment, health‐sickness, symptom level, diagnostic severity and demographic data, to predict to 2‐year outcome measures of level of functioning, health‐sickness, and symptoms for a sample of 145 adult psychiatric first‐admissions. It was hypothesized that IQ as an indicator of cognitive ability, or of general ability to adapt, would predict positively to improvement over the 2‐year period. Data analysis was conducted with bivariate correlations and multiple regressions, using both absolute‐level and residualized outcome variables. IQ showed modest, significant relationships with all absolute outcome indices and six of seven residualized measures, especially for a subsample of those with non‐average IQ scores. Regressions showed that IQ provided independent prediction of symptom outcomes.