Background: Data on psychological harm in multiple endocrine neoplasia type 2 (MEN2) are scarce. Objectives: The aim of this study was to assess anxiety, depression, quality of life, and coping in long-standing MEN2 patients. Patients and Methods: Patients were 43 adults (age >= 18 years) with clinical and genetic diagnosis of MEN2 and long-term follow-up (10.6 +/- 8.2 years; range 1-33 years). This was a cross-sectional study with qualitative and quantitative psychological assessment using semi-directed interviews and HADS, EORTC QLQ C30, and MINI-MAC scales. Adopting clinical criteria from 2015 ATA Guidelines on MEN2, biochemical cure (39%; 16/41), persistence/recurrence (61%; 25/41), and stable chronic disease (22/41) of medullary thyroid carcinoma (MTC) were scored. Pheochromocytoma affected 19 (44%) patients, with previous adrenalectomy in 17 of them. Results: Overall, anxiety (42%; mean score 11 +/- 2.9; range 8-18; anxiety is defined as a score >= 8) and depression (26%; mean score 11 +/- 3.8; range 8-20; depression is defined as a score >= 8) symptoms were frequent. Patients who transmitted RET mutations to a child had higher scores for weakness-discouragement/anxious preoccupation and lower scores for cognitive, emotional, and physical functioning (p < 0.05). Feelings of guilt were present in 35% of patients with mutation-positive children. Lower mean score values for depression and anxiety and higher scores for role, cognitive, and emotional functioning were noticed in 33 patients who were well-informed about their disease (p < 0.05). Fighting spirit was more frequently found in patients with multiple surgical procedures (p = 0.019) and controlled chronic adrenal insufficiency (p = 0.024). Patients with MEN2-elated stress-inducing factors had lower scores for fighting spirit and cognitive functioning and higher scores for insomnia and dyspnea (p < 0.05). Eleven patients required sustained psychotherapeutic treatment. Mean global health status was relatively good in MEN2 cases (68.1 +/- 22.3), and the cured group had higher physical functioning (p = 0.021). Conclusions: Psychological distress is likely chronic in MEN2 patients. This study identified diverse MEN2-related factors (degree of information on disease, mutation-positive children, number of surgeries, comorbidities, stress-inducing factors, and cure) interfering positively or negatively with the results of the psychometrics scales. The active investigation of these factors and the applied psychological assessment protocol are useful to identify MEN2 patients requiring psychological assistance.