The Dual Model of Passion (Vallerand, 2003) has dominated the literature on passion over the last decade differentiating between harmonious and obsessive passion and its psychological determinants. At the same time however, little is known about the negative and positive effects of passion among therapists and counsellors. The current study examines firstly, the effect of the presence of passion on Irish Therapists’ wellbeing; and secondly, the contribution of harmonious and obsessive passion to Irish Therapists’ levels of wellbeing (after controlling for age and years in practice). This study was carried out with 133 therapists in Ireland. Using Pearson’s correlation and hierarchical multiple regression, results show that experiencing passion for work is not associated with psychological flourishing, emotional or social well-being, however it is associated with psychological well-being. Furthermore, only harmonious passion predicted higher scores of flourishing, emotional and social well-being and both high levels of harmonious and lower levels of obsessive passion predicted levels of psychological well-being of therapists. The results are discussed in the context of therapists’ practice, education and self-care.