Benign biopsies are an inevitable part of any screening programme. They add significantly to the psychological and financial 'cost' of screening and so should be kept to a minimum. To identify possible means of reducing these false positive results we have reviewed the mammographic features of 108 benign lesions removed during prevalent round screening and correlations were sought with the pathological findings. The commonest mammographic abnormalities leading to benign biopsy were non-comedo type suspicious calcification (29%), poorly defined mass (21%), architectural distortion (19%) and a well defined mass (18%). The histological correlates were: non-comedo type suspicious calcification (fibrocystic change 60%, sclerosing adenosis 35%, and radial scar/CSL 13%), poorly defined masses (fibrocystic change 37%, fibroadenomas 37%, and sclerosing adenosis 25%) and architectural distortion (radial scar/CSL 61% and fibrocystic change 26%). Methods of reducing screening provoked benign biopsies are discussed.