This study examined posttraumatic growth in 30 male veterans captured and held as prisoners of war during the Vietnam War. Participants were assessed with structured diagnostic interviews administered by trained clinicians as well as with the Posttraumatic Growth Inventory (PTGI) and other questionnaires measuring dispositional optimism, religious coping, social supports, and purpose in life. Mean age (standard deviation-SD) of participants was 66.7 (6.0) years. Mean total PTGI score (SD) was 66.3 (17.5), indicating a moderate degree of posttraumatic growth. The most strongly endorsed items corresponded to the Appreciation of Life and Personal Strength factors. The group as a whole was optimistic and reported moderate use of positive religious coping. Posttraumatic growth did not significantly differ in repatriates with and without psychopathology, but it was significantly positively correlated with dispositional optimism. In the final regression model, length of captivity and optimism were significant predictors of posttraumatic growth. Our findings confirm that it is possible to achieve long-lasting personal growth even in the face of prolonged extreme adversity. Prospective studies are needed to further evaluate whether pre-existing traits such as optimism can predict growth after trauma.