In an attempt to find out whether phaeochromocytoma could be screened by questioning, the authors have recorded in a population of 2585 hypertensive patients the symptoms known to be most frequently associated with the tumour, i.e. headaches, palpitations and sweating attacks. Since 72.4% of the entire population reported one or another of these complaints, no single symptom could be taken as suggestive of phaeochromocytoma. However, only 6.5% of the patients reported all three symptoms and could therefore be considered as forming a subgroup likely to have the tumour. Patients in this subgroup differed from the others in the predominance of females (p less than 0.01), the higher frequency of anxiety (p less than 0.01) and above all, the higher incidence of phaeochromocytoma (5.9% as against 0.04%; p less than 0.01). The symptomatic triad (headaches, palpitations, sweating attacks) has a specificity of 93.8%, a sensitivity of 90.9% and an exclusion value of 99.9% for the diagnosis of phaeochromocytoma. Its presence in hypertensive patients justifies systematic assays of blood or urinary catecholamines. In its absence, the probability of phaeochromocytoma is inferior to 1 in 1 000.