Forty-nine patients with posttraumatic complex regional pain syndrome (CRPS) of the upper extremities were investigated by laser Doppler flowmetry (LDF) with wavelet-analysis of skin blood flow oscillations. Clinical evaluation of sympathetically maintained pain was carried out after the thoracoscopic clipping above and below the Тh3 ganglion of sympathetic chain) in 33 patients and after the perivascular sympathectomy at the level of brachial artery and veins) in 16 patients. The objective diagnosis of sympathetically maintained pain was created with LDF; it was directed specially to discovery of sensory-sympathetic coupling in CRPS. Sensitivity of preoperative LDF-diagnosis was 90.2%, specificity - 87.5%, positive predictive value - 97.3%, negative predictive value - 63.6%, diagnostic effectiveness - 89.8%.