To date, little empirical research has been conducted to support the claim that outdoor adventure education (OAE) develops desirable psychological characteristics in participants. This study examined the effects of an OAE foundation degree curriculum on positive psychological development. Fifty-two students (26 OAE students, 26 controls on an unrelated course), aged 16-39 years, completed a battery of positive psychological questionnaires (at the start of their respective courses and 3 months later) measuring hardiness, mental toughness, self-esteem, self-efficacy, dispositional optimism, and positive affectivity. OAE curriculum activities included rock-climbing, navigation training, countryside leadership, gill-scrambling, and open canoeing. Control students were enrolled on a classroom-based travel and tourism college course. Inferential multivariate statistics revealed non-significant (p greater than 0.05, partial h2 = 0.38) improvements by the OAE group across several psychological constructs. Significant effects (p less than 0.05, partial h2 = 0.15) for the cohort were revealed for total hardiness. No significant gender differences were reported. The non-significant overall effect is interpreted in terms of sample size, OAE activities, and measured personality styles. The implications of these results are discussed relative to previous findings and in terms of psychological theory.