The multifaceted self refers to how non-clinical individuals perceive themselves as possessing a more sophisticated self-compared to others by accumulating pairs of opposing positive traits. Conversely, depressed individuals are more multifaceted on negative traits, revealing an absence of self-enhancement strategies, which are known to be associated with psychological adjustment. A pre-/post-intervention study was conducted to observe the changes in multifaceted self and mental health following an 8-week multi-site Mindfulness-Based Interventions (MBIs) targeting depression and anxiety disorders. Among the 24 participants, changes occurred across all outcome measures (i.e., trait mindfulness, anxiety, depression and self-compassion). Participants displayed reduced self-negativity, a more positive view of others, and although they still maintained a more negative self-view compared to their view of others, this improved with the MBIs. Mindfulness and social comparison processes are discussed. The multifaceted self serves as a relevant methodological approach to assess mental health adjustment in MBIs.