The cell proliferation rate has been used to assess the biological aggressiveness and the metastatic potential of breast carcinoma. Different methods (flow cytometric S phase and proliferation associated antigens) have been used to assess the rate of proliferation previously. In this preliminary study, the cell proliferation rate of normal (N=45), benign (N=29) and invasive breast tumor tissue (N=70) has been quantified in vitro by ATP bioluminescence assay. Next, individual prognostic factor (tumor grades, lymph node involvement, estrogen and progesterone receptor and HER-2 status) has been correlated with the level of metabolic rate (ATP). The results showed that invasive tumor had the highest level of ATP bioluminescence compared with that of benign tumor (mean difference=1.97) and the normal breast tissue (mean difference=2.75). In addition, ATP level positively correlated with the number of axillary lymph node involvement (r_spearman=0.433, P=0.021). These findings suggested that the measurement of ATP level may serve as a mean for the detection of cell proliferation and hence a surrogate marker for disease prognosis.