Since the beginning of the 20th century, the principles of the experimental method in biological sciences have been progressively applied in biomedical and clinical research. After the pioneering work of AB Hill et al, biostatistics became a fundamental tool in the appraisal of new therapeutic agents or methods, and of diagnostic tests. From 1990 on, «Evidence based Medicine» has been added to it. This journal opens in this issue a section containing critical analysis of articles published in the medical literature deserving the attention of its readers. However, as several other medical journals have stressed, we recommend that the conclusions of these analysis should not be used as a substitute for clinical judgment and they do not represent an official position of our journal. Revista Médica de Chile welcomes the new Section and invites contributions to it (Rev Med Chile 2003; 131: 835-6