Objective To investigate the association between prodromal symptoms of schizophrenia, autonomic activity, and personality functioning. Method 10 adolescents underwent semi-structured interviews assessing prodromal symptoms of schizophrenia and personality functioning. Cardiac activity was recorded at baseline, during the clinical interviews, and at recovery to assess concurrent changes in autonomic functioning. Results During the assessment of prodromal symptoms of schizophrenia, participants increased sympathetic activation compared to the recovery condition, and reduced vagal activation compared to the assessment of interpersonal functioning. Conclusions The findings highlight the importance of integrating the autonomic assessment in clinical psychiatric and psychological practice.