The present invention is related to a stereotaxic frame for extremities that ensures that the extremity position is fixed and reproducible; keeping the same geometric conditions of the measurement or treatment devices regards the extremity, or part thereof, during the study or therapy. The frame comprises a positioning and fixing holder for the extremity and a measuring or treatment system, that includes a geometric locus where the measurement or treatment device is allocated, ensuring that the relative position of said device regards the region of the extremity under examination or treatment is reproducible.