In-session emotional processing is a central component of psychotherapy, but little is known about the types and the quality of emotional processing individuals engage in daily life. An ecological momentary assessment (EMA) schedule has been validated to assess distinct emotional experiences as they emerge in daily life. It remains an open question whether changes observed in distinct emotional experiences over a week of assessment are related to in-session self-esteem. In total, N = 42 university students participated in a one-week assessment of emotions using ecological momentary assessment, as well as in a one-session experiential task of resolving self-criticism (using a two-chair dialogue from emotion-focused therapy). The emotions in daily life were self-reported by the participants on a regular basis, and self-esteem was assessed three times during the two-chair dialogue. Two-level hierarchical linear models reveal emotional changes in daily life, and in-session self-esteem is introduced as predictor at level 2. In-session self-esteem was correlated with symptom levels. The results showed that changes in primary maladaptive emotions in the one-week assessment were predicted by state and trait components of in-session self-esteem, which took place at the outset of the EMA. Trait-components of self-esteem were linked with the level of symptoms, whereas state-components of self-esteem were not. The present study underscores the importance of extending research from within-session observations of emotional processing towards daily life.