Mammography is widely used for imaging the breast, but is known to be less effective in evaluating the younger dense breast. In this study the ability of telediaphanography in conjunction with Doppler ultrasound (TDDU) to detect breast carcinomas was assessed. Light absorption, determined by the number of blood cells per unit volume of breast, results in the detection of an opaque lesion. Subsequent Doppler ultrasound detects the neovascularization at the periphery of tumours. In total, 178 patients were investigated without prior knowledge of the mammographic findings. This consisted of 69 patients presenting to the symptomatic breast clinic with normal mammograms and 109 patients with mammographic detected abnormalities (mean age 54 years). There were 95 neoplastic lesions. The sensitivity and specificity were: telediaphanography alone 73% and 82%; TDDU 61% and 92%, respectively. TDDU was less sensitive for small and impalpable tumours, and did not detect ductal carcinoma in situ (26 false negatives, mean diameter of 1.1 cm (SD of 0.3 cm)). Subsequent Doppler ultrasound did not further increase the sensitivity of the examination, but did increase the specificity. Patients with locally advanced breast cancers showed dramatic changes on repeated optical/Doppler examinations, in concordance with response to chemotherapy. The combined optical/Doppler instrument, with its low sensitivity, is not suitable for screening, even in the young dense breast, but may have a role in assessing the response of large tumours to chemotherapy.