Judgments of trustworthiness from faces are made rapidly, without intention, and may be supported by localized neural structures. Other work demonstrates that the left frontal cortical region is involved in approach motivation, whereas the right frontal cortical region is involved in avoidance motivation. In the current work we integrated these two streams of research to test an approach-avoidance motivational model of trustworthiness judgments. We tested whether global differences in hemispheric lateralization relate to trust judgments, which may exist due to mutual relationships with approach and avoidance motivation. The left (right) frontal cortical region has been found to relate to approach (avoidance) motivational processes, and approach (avoidance) motivation may relate to trusting (distrusting). Correspondingly, the current work finds that faces presented preferentially to the left versus right hemisphere (through manipulated visual field presentation) were trusted more often (Study 1), and trustworthy versus untrustworthy faces evoked a correlate of preferential left frontal cortical activity (right visual field bias; Study 2). These studies extend accounts that posit hemispheric specialization of approach/avoidance motivation to the domain of judging trustworthiness, thereby integrating disparate literatures on social judgment, face perception, and cortical asymmetries in approach/avoidance motivation.