Objective: To inventory the diagnostic methods used in patients with clinically occult, radiologically suspect breast lesions., Design: Enquiry., Method: The departments of radiology of all Dutch hospitals were sent a list in January 2000 containing questions concerning the number of thread localizations in 1999 and the use of cytological or histological needle diagnostics with image monitoring prior to surgical intervention in clinically occult, radiologically suspect breast lesions. Of the 120 questionnaires mailed, 74 (62%) were completed and returned by clinics throughout the country., Results: Fifty-one of the 74 hospitals (69%) had prior to operation carried out histological or cytological examinations and in these 51 hospitals this was done in 1743 of the 2857 lesions (61%): fine-needle aspiration cytology was performed in 1046 (/1743 = 60%; /4140 lesions in all 74 hospitals = 25%) and/or histological needle biopsy in 784 (45%; /4140 = 19%)., Conclusion: In less than half of all non-palpable breast abnormalities non-surgical methods of diagnosis are used, histological needle biopsy less often than fine needle aspiration cytology.