In this advanced and stressful world, most of young adults use imaginations and fantasies as a coping mechanism to deal with their negative emotions. However, the impact of these subjective experiences on mental well-being of youth varies. The purpose of this study was to explore the relationship and predictive effect of daydreaming, escapism and partner fantasies on mental well-being of youth. A quantitative cross-sectional survey method was used in the current study. A sample of 311 participants, aged from 18-24 years, was selected by using probability sampling method, from two faculties of the University of Gujrat. Scales used in this study to collect data were; Dysfunctional Daydreaming Scale (DDS), Escapism Motivation Scale, Ideal Partner and Ideal Relationship Scales and The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS). First, the reliability of all these scales were measured and then data was analyzed by using descriptive statistics, correlational analysis and hierarchical multiple regression. Results showed that dysfunctional daydreaming was negatively related to mental well-being while self-expansion and all ideal perception traits related to partner, self and relationship were positively related to mental well-being. The complete regression model explained 21.5% variance in mental well-being, which showed that these variables had significantly predict change, with dysfunctional daydreaming, partner status and self-warmth being negative predictors while escapism, self-attractiveness and relationship intimacy were positive predictors of mental well-being of youth. The findings can be helpful for educators and clinicians to guide youth by encouraging them to engage in constructive imaginations that are goal-oriented and emotionally enriching.