In our institute, the oestrogen and progesterone receptors of breast cancer samples are analyzed by biochemistry and immunohistochemistry. The purpose of this study is to evaluate and compare both techniques and establish whether one of them should be used in preference to the other. The probability of getting a positive or negative result with each technique was the same regardless of the method used as reference. The biochemical method uses a larger volume of tissue to determine the receptor status than immunohistochemistry. In some cases, this means a loss of valuable information. If we only use one technique, there is the potential to misclassify +/- 11% of patients. According to these results and in the knowledge that the major interest of steroid receptors' status remains in the domain of therapeutic decisions, we advise using immunohistochemistry first and biochemistry if there is a negative result. This would spare tumour tissue for new research studies.