Passions have the potential to fill people’s lives with meaning. However, there is a duality to the concept, where harmonious passion reflects a more volitional engagement, whilst obsessive passion reflects a more controlled, contingency driven engagement style. The aim of this study was to explore the assumption that self-esteem represents a persistence-promoting contingency contributing to a more obsessive activity engagement style. In order to tackle this assumption, the function of global and domain specific self-esteem in relation to harmonious and obsessive passion, and affective outcomes was considered. Also, to gain a better understanding of the function of self-esteem in relation to people’s passions in the real world, the sample of 210 participants (92 females and 118 males) was split into one high obsessive passion-group (HOP), and one low obsessive passion-group (LOP). Results showed that the HOP-group had significantly more domain specific self-esteem, and also that this specific self-esteem was the main source of positive affect. In addition, the HOP-group had significantly more negative affect, as well as a more unstable self-esteem compared to the LOP-group. In conclusion, results therefore supported the notion that more obsessive individuals also have a more contingent activity engagement where their self-esteem is perceived as continually on the line, compared to their harmonious counterparts. Such a contingent engagement in a passionate activity seems to give both short term boosts in self-esteem and positive affect, as well as contribute to more ill-being and social problems over time.