The assessment of completeness of a sympathectomy can be objectively recorded and documented by dermofluorography. This method enables measurement of increased skin perfusion which leads to an earlier appearance time and steeper initial rise in fluorescence of intravenously administered sodium fluorescein. The most significant parameters are the quotients of the average appearance time and the initial rise in fluorescence of the untreated versus treated leg. Following a successful lumbar sympathectomy, these parameters were outside 3 standard deviations of the values obtained from healthy test persons.