This study examined the effects of optimism following traumatic stress and pathways through which optimism may act. Rescue and recovery workers at the crash site of US Air Flight 427 (n= 159) were studied 2, 6, 9, and 12 months after the crash to examine optimistic outlook, social support, coping, and stress. As predicted, a more optimistic disposition was associated with less self-reported distress, less use of avoidant and wishful-thinking coping strategies, greater use of problem-focused and seeking-social-support coping, and greater availability of social support. Contrary to expectations, coping did not account for the relationships observed between optimism and stress responding. Social support explained some of the effects of optimism on coping and stress, but these mediational effects varied over time. Findings suggest that optimism affects stress and coping directly and indirectly by affecting how much social support is available.