Reduced social impairment and improved life satisfaction are important objectives in group treatment for patients with personality dysfunction. Knowledge regarding patient characteristics and group treatment processes that contribute to these outcomes, however, remains limited. Dispositional connectedness, the valuing of interpersonal connections, may be an important patient factor that influences patients' experience of group treatment in ways that facilitate therapeutic benefits. The present study investigated the roles of dispositional connectedness and group engagement in contributing to improvement in social functioning and life satisfaction through integrative group treatment for personality dysfunction. Seventy-nine patients who completed an integrative group treatment programme were assessed for dispositional connectedness at baseline and social functioning and life satisfaction at pretreatment and posttreatment; each also provided ratings of group engagement during treatment. Regression analyses using bootstrap confidence intervals found significant indirect effects for dispositional connectedness regarding improvement in both social functioning and life satisfaction, through the mediating effect of group engagement. Thus, patients who entered treatment with tendencies towards interpersonal connectedness perceived a higher level of engagement in the group environment. Group engagement in turn contributed to greater improvement in social functioning and to greater improvement in life satisfaction following treatment. The findings indicate dispositional connectedness as a salient characteristic in selecting patients for group treatment and highlight the role of an engaged interpersonal climate in facilitating improvement in social functioning and life satisfaction. K E Y W O R D S connectedness, engagement, group treatment, life satisfaction, social functioning