Purpose: The study evaluated a group-based cognitive behavioral intervention aimed at promoting the quality of life and the psychological well-being of recently diagnosed multiple sclerosis (MS) patients (up to 3 years since the diagnosis).Method: The study involved 85 patients [59% women; mean age 37, SD = 12.3; 94% with relapsing-remitting MS; Expanded Disability Status Scale (EDSS) between 1 and 4]. A quasi-experimental study design was applied; 54 patients (intervention group) participated in five group sessions, a 6-month post-intervention and a 1-year follow-up; 31 patients (comparison group) participated in activities routinely provided to recently diagnosed MS patients. Measures of Quality of Life (SF-12), Depression (CESD-10), Affective well-being (PANAS) and Optimism (LOT-R) were assessed.Results: At the 6-month post-intervention, mental health increased in the intervention group and decreased in the comparison group, whereas negative affect decreased in the intervention group and increased in the comparison group. At the 1-year follow-up, mental health and optimism increased in the intervention group and decreased in the comparison group.Conclusions: Preliminary evidence suggests that the proposed intervention fosters the quality of life and the psychological well-being of recently diagnosed MS patients by reducing negative affect and promoting mental health and optimism, particularly in the long term.Implications for RehabilitationPreliminary evidence suggests that a group-based cognitive behavioral intervention focused on identity redefinition, sense of coherence and self-efficacy promotes the quality of life (increased mental health) and psychological well-being (decreased negative affect and increased optimism) of recently diagnosed MS patients (up to 3 years since the diagnosis).The first years following the MS diagnosis should be considered a good time for a psychological intervention aimed at promoting the patient’s adjustment to the illness.Strategies should be found to increase the participation of recently diagnosed MS patients in psychological interventions.