The aim of the study was to examine mediational effects of positive and negative emotions (PEs and NEs) on the relationship between cognitive appraisal and coping after myocardial infarction (MI). Subjects were 163 patients assessed a few days after their first MI episode for cognitive appraisal using the Situation Appraisal Questionnaire developed by Wrzesniewski and based on the Lazarus theory. The participants' current emotional state and coping strategies were evaluated with Polish versions of the PANAS and CISS-S, respectively. The data were analyzed using the boostrapping procedure. Resultant models turned out to be similar for threat and loss appraisal, where PEs mediated task-oriented coping, while NEs were found to mediate emotion-oriented coping. A different relationship was found for challenge. Due to a significant intercorrelation among appraisals, mediational models for threat and loss were re-analyzed when controlling for challenge. Nevertheless, even if a situation is perceived as highly stressful, both positive and negative emotions can emerge, resulting in strategies that serve different functions to meet external and internal demands.