Blood circulation was measured by laser doppler flowmetry in fasciocutaneous flaps of 24 patients who underwent reconstructive surgery for mammary carcinoma. 19 of the 24 patients had clinical signs of deficient circulation in the flaps. 14 patients were treated with electrical nerve stimulation (ENS) and 10 with placebo-ENS. Varying degrees of necrosis developed in 8 of the 10 patients who received placebo stimulation but in none of those treated with ENS. In the 5 patients with good capillary refilling and no signs of stasis or oedema before treatment, only minor increases in blood flow occurred after ENS.