Recent promotion of breast cancer screening has increased the demand for mammography services and well-trained mammographers. To determine whether focused instruction, which may occur in continuing medical education courses, is effective in imparting mammography skills and knowledge, an instructional program was developed and evaluated. Seventeen physicians were tested before and after six 1-hour instructional sessions about breast disease and cancer screening, mammogram interpretation, and determining appropriate patient disposition. Twelve weeks after instruction, subjects demonstrated significant improvement in factual knowledge, in decision-making ability regarding patient disposition, and in recognition of benign disease on mammograms. There also was significant improvement in specificity, but no improvement in cancer detection. Further, no correlation between participants' subjective self-assessment of improvement and their actual performance on the postinstruction evaluation was found. Evaluation of instructional programs is necessary to determine their effectiveness, and promotes improvement in instructional offerings.