A new methodology to obtain tissue samples from breast tumors through fine needle aspiration is described. This consists of a screwdriver like movement of the needle and continuous aspiration. The tissue is embedded in a blood clot, fixed in 10% formalin and routinely processed for histopathological study. From March 1987 to March 1990 this technique was applied in 84 patients. Ten did not have conventional histopathological study. The 74 patients studied had 76 tumors. Six cases (7.9%) had "unsatisfactory" specimens and nine (11.8%) only allowed cytological diagnosis. The 61 remaining samples (80.3%) were considered "sufficient" for histopathological study. The new methodology had a sensitivity of 95.5% specificity of 100% and positive predictive value of 100%. In this series there were no false positive cases.