Background: Very little is known about the neuropsychological correlates of adaptive functioning in people with intellectual disabilities (ID). This study examined whether specific cognitive deficits and demographic variables predicted everyday functioning in adults with ID. Method: People with ID (n = 101; ages 19-41 years; mean education = 11 years; 34% women; 54% competitively employed; 41% with mild ID) completed a comprehensive neuropsychological battery grouped into four cognitive domains: processing speed, verbal memory and comprehension, visual perception/constructive function, and executive function. In addition, parents completed an 89-item rating scale developed to assess a wide range of independent living skills. Results: Confirmatory factor analysis results confirmed a correlated four-factor model of cognitive function and a unidimensional model of everyday functioning. Furthermore, structural equation modelling results supported the predictive relationship of verbal memory/comprehension and employment status (standardized regression coefficients 0.45, 0.22, P less than or equal to 0.01 for each) to measures of everyday functioning. The two variables together explained 35% of the variance in everyday functioning. Conclusions: Both general cognitive dysfunction and specific verbal memory and comprehension deficit impair daily functions in people with ID. These findings have implications for predictive models of adaptive functioning, and for cognitive rehabilitation and deficit compensation strategies for this group. (Contains 1 figure and 4 tables.)