Background: Chronic stress worsens the quality of life (QOL) of lupus patients by affecting their physical and psychological status. The effectiveness of a cognitive-behavioural intervention in a group of patients with lupus and high levels of daily stress was investigated. Methods: Forty-five patients with lupus and high levels of daily stress were randomly assigned to a control group (CG) or a therapy group (TG); they received cognitive behavioural therapy (CBT) which consisted of ten consecutive weekly sessions. The following variables were evaluated at baseline and at 3, 9 and 15 months: (1) stress, anxiety, depression, (2) Systemic Lupus Erythematosus Disease Activity Index, somatic symptoms, number of flares, (3) anti-nDNA antibodies, complement fractions C3 and C4 and (4) QOL. A multivariate analysis of repeated measures and various analyses of variance were carried out. Results: We found a significant reduction in the level of depression, anxiety and daily stress in the TG compared to the CG and a significant improvement in QOL and somatic symptoms in the TG throughout the entire follow-up period. We did not find any significant changes in the immunological parameters. Conclusions: CBT is effective in dealing with patients suffering from lupus and high levels of daily stress as it significantly reduces the incidence of psychological disorders associated with lupus and improves and maintains patients’ QOL, despite there being no significant reduction in the disease activity index.