Research on the validity of the behavioral inhibition system/behavioral approach system (BIS/BAS) scales focused on adolescent, student and adult populations. This study is the first to examine the psychometric properties of the BIS/BAS scales in a community (n = 368) and a clinical sample (n = 160) of older adults. Exploratory structural equation modelling with target rotation to the Carver and White model supported the construct validity of the BIS/BAS scales. Internal consistencies of the scales were generally satisfactory. Female participants scored higher on BIS and BAS-Reward Responsiveness compared with males. The community-dwelling sample scored higher on BAS-Drive and BAS-Reward Responsiveness compared with the clinical sample. Concerning the nomological net, BIS was positively related to Anxiety, Depression, maladaptive coping strategies, Neuroticism and Cluster C personality disorders. BAS was positively related to Openness, Extraversion, Active Confronting and Cluster B personality disorders and negatively related to the schizoid personality disorder. The BIS/BAS Scales are a useful instrument for measuring Gray's theory of personality in older adults.