BACKGROUND: Although guidelines do not recommend computerised tomography (CT), positron emission tomography (PET) or magnetic resonance imaging (MRI) for the staging or follow-up of asymptomatic patients with non-metastatic breast cancer, they are often requested in routine clinical practice. The aim of this study was to determine the staging and follow-up patterns, and relative costs in a large population of breast cancer patients living and treated in a Southern Italian region. METHODS: We analysed the clinical computerised information recorded by 567 primary-care physicians assisting about 650 000 inhabitants in the Campania region. Patients with non-metastatic breast cancer were identified and divided into calendar years from 2001 to 2010. The number of diagnostic tests prescribed per 100 patients (N/Pts) and the mean cost per patient was determined 3 months before diagnosis and up to 1 year after diagnosis. Costs are expressed in constant 2011 euros. RESULTS: We identified 4680 newly diagnosed cases of asymptomatic non-metastatic breast cancer. N/Pts increased significantly (P<0.0001) from 2001 to 2010. The mean number of prescribed mammograms, bone scans, abdominal ultrasound and chest X-rays ('routine tests'), and costs was unchanged. However, the number of CT, PET scans and MRI ('new tests')prescriptions almost quadrupled and the mean cost per patient related to these procedures significantly increased from [euro ]357 in 2001 to [euro ]830 in 2010 (P<0.0001). CONCLUSIONS: New test prescriptions and relative costs significantly and steadily increased throughout the study period. At present there is no evidence that the delivery of new tests to asymptomatic patients improves breast cancer outcome. Well-designed clinical trials are urgently needed to shed light on the impact of these tests on clinical outcome and overall survival.