Objective. The aim of this study was to investigate the relationship between stressful life events (LESs) and its effect on the initiation of Graves' disease (GD) and toxic nodular goitre (TNG). Patients and method. Forty-five patients with GD, 24 patients with TNG and 36 healthy control (CG) were included to the study. Graves and TNG patients had diagnosed within the last 12 months, with clinical and biochemical confirmation in Endocrinology Metabolism Outpatient Clinic of Cerrahpasa Medical School. The Holmes-Rahe Stress Scale and the Life Experience Survey (LES) was the psychological evaluation instrument used in this study. Results. There was no significant difference according to Holmes-Rahe scale (Graves & TNG P = 0.329, Graves & Control P = 0.115, TNG and control P = 0.571). According to LES scale when negative event number, positive event number, neutral events and their effects are considered, between Graves and TNG groups no statistically difference was observed (P = 0.139, P = 0.083, P = 0.167, P = 0.162, P = 0.861). The number and impact of negative SLEs were significantly higher in GD compared to CG (P = 0.015, P < 0.001). Conclusion. According to LES scale GD patients has significant difference with respect to CG when negative event number and impact are considered.