Context: Adrenal and extra-adrenal phaeochromocytoma are chromaffin cell-derived tumours that are discovered due to classical symptom triad with headache, sweating and palpitations combined with persistent or paroxysmal hypertension. However, an increasing proportion of phaeochromocytoma seems to be discovered incidentally upon abdominal imaging. Objective: To specify the exact circumstances of discovery of adrenal and extra-adrenal phaeochromocytoma. Design and patients: Four German endocrine centres participated in this retrospective study. Medical records of 201 patients with adrenal and extra-adrenal phaeochromocytoma who were diagnosed between 1973 and 2007 were analyzed. Results: The typical triad of symptoms was found only in 10% of cases. Ten percent of patients presented were without clinical symptoms and 6.1% were normotensive. Documented blood pressure peaks occurred in 44.1% of cases. In 24 patients (12.2%), phaeochromocytoma was malignant. Before 1985, !10% of cases were incidentally discovered, whereas thereafter the frequency was O25% (29.4% of the total study population). Patients with incidentally detected phaeochromocytoma were significantly older (53.1G1.9 vs 47.0G1.3 years; P!0.05) and often had less blood pressure peaks (37.0 vs 70.7%; P!0.001) than patients in whom the diagnosis was suspected on clinical grounds. Of phaeochromocytomas 94.4% were intra-adrenal tumours, of which 12.9% were bilateral. Bilateral tumours were significantly smaller than unilateral tumours (36.6G14.7 vs 52.5G34.3 mm; P!0.05), whereas extra-adrenal tumours had a mean diameter of 52.6G28.7 mm. Conclusions: Owing to better availability and accessibility of imaging procedures, the number of incidentally discovered phaeochromocytoma is increasing and reaches nearly 30% in our study population. Every adrenal incidentaloma should be investigated for the presence of phaeochromocytoma.