The goal of the present study was to examine the influence of age and gender on the factor structure of the Schizotypal Personality Questionnaire (Raine, 1991). Schizotypal traits were assessed in a random sample of mature, adult community volunteers (average age 40 years). Four competing models of the latent factor structure were tested in the full sample (N = 352). The resulting three-factor model was then assessed separately in males and females and in stratified subsamples, reflecting three age cohorts. The results showed that, in mature adults, males had higher scores than females on No Close Friends and Constricted Affect whilst females had higher scores on Social Anxiety and Odd Beliefs subscales. Older adults were also characterized by lower total SPQ scores than those reported previously for younger adults. Despite the presence of age and sex-related differences in mean SPQ scores, a three-factor model of schizotypal personality best characterized the SPQ responses from mature adults, replicating that reported previously in highschool and university-aged samples. The implications of these findings of SPQ factor structure invariance, across age and gender, are discussed with reference to studies investigating neurocognitive correlates of schizotypy (i.e. endophenotypes). (c) 2005 Elsevier Ltd. All rights reserved.