Self-criticism is a transdiagnostic factor of significant clinical relevance. Research has studied its detrimental role on mental health without discriminating how this differs based on individual psychological functioning. Furthermore, little research has considered the lack of emotional awareness as an essential competence that contributes to dysfunctional self-critical processes and, consequently, to psychopathological outcomes. The objective of the study was to investigate how different forms of self-criticism are associated with specific symptoms, considering social anxiety, obsessive-compulsive, and eating disorder symptoms. Furthermore, we wanted to explore the role of alexithymia in this relationship. The sample comprised 564 subjects (M = 35.12, SD = 12.8), 389 females and 175 males. Participants completed online questionnaires to investigate levels of self-criticism, alexithymia, and specific symptoms. Hierarchical regression and path analyses showed that aspects of self-criticism have different importance in psychopathological features. Furthermore, the subscales of alexithymia differently mediate the relationship between self-criticism and symptomatological features, depending on the type of feature considered (social anxiety, eating or obsessive-compulsive). In light of the results, since self-criticism is a contributing factor to the onset and maintenance of many mental disorders, it becomes important to distinguish its specific characteristics and how they are linked to the disorders. A better understanding of these processes would help to prepare more targeted interventions.