The article analyzes the relationship between comorbid changes in the mental state of individuals who have experienced loss and have a history of social anxiety disorder. The aim of the study was to analyze indicators of accompanying changes during the grieving process (level of depression, level of anxiety, avoidance tendencies, social maladjustment, subjective well-being, and life satisfaction) in individuals with social anxiety disorder who have experienced the loss of a significant person. The study involved 191 individuals who sought psychotherapeutic help for prolonged grief after the loss of a loved one between 2018 and 2020. The results suggest that individuals suffering from social anxiety disorder and experiencing loss of a loved one are more prone to avoiding social experiences, which affects the severity of depressive symptoms and psychological distress associated with the traumatic experience within the grieving process. The results confirmed that individuals with a history of social anxiety disorder and complicated grief demonstrate lower life satisfaction and higher levels of social impairment compared to those without complicated grief, regardless of the history of social phobia. According to the research findings, social phobia in the personal history is not an independent factor in the development of complicated grief. The degree of avoidance of social interaction after loss, level of distress, and typical beliefs within the clinical picture of social phobia can be modifying factors in the pathogenesis of complicated grief.