In The Netherlands, relatively more patients (20%) with amyotrophic lateral sclerosis (ALS) die due to euthanasia or physician-assisted suicide (EAS) compared with patients with cancer (5%) or heart failure (0.5%). We wanted to gain insight into the reasons for ALS patients requesting EAS and compare these with the reasons of cancer and heart failure patients. Knowing disease-specific reasons for requesting EAS may improve palliative care in these vulnerable patients. The data used in the present study were derived from the Support and Consultation in Euthanasia in The Netherlands (SCEN) evaluation study. This study provided consultation reports and questionnaires filled out by the attending physicians from 3,337 consultations conducted by SCEN physicians in situations where a patient requested EAS. For this study we selected data on all ALS patients (n = 51), all heart failure patients (n = 61), and a random sample of 73 cancer patients. The most frequently reported reasons for unbearable suffering were: fear of suffocation (45%) and dependency (29%) in ALS patients, pain (46%) and fatigue (28%) in cancer patients, and dyspnea (52%) and dependency (37%) in heart failure patients. Somatic complaints were reported more frequently as a reason for EAS by cancer patients [odds ratio (OR) 0.20, 95% confidence interval (CI) 0.09-0.46] and heart failure patients [OR 0.16, 95% CI 0.05-0.46] than by ALS patients. ALS patients should be helped in a timely fashion to cope with psychosocial symptoms, e.g., by informing them about the low risk of suffocation in the terminal phase and the possible means of preventing this.