The aim of this study was to evaluate a new modified visual analog scale, called the dolorimeter, together with a verbal rating scale (VRS) and a linear visual scale (VAS), in the measurement of acute postoperative pain. The scales were evaluated with reference to their sensitivity, reliability and validity, and correlation. During the study 200 patients 11-70 years of age (125 men, 75 women) were interviewed after orthopedic surgery to ascertain the intensity of the pain. We had the patients judge the intensity of pain before and 1 h after giving analgesics by using the dolorimeter, VRS, and VAS. At the end of the examination, we asked the patients whether the pain had decreased or not which method they preferred, and why they preferred this method. The results of this interrogation proved that the sensitivity of the VRS is low; its parameters overlap greatly on the analog, scale, and it is therefore too rough to be a sufficient measurement of pain. On the other hand, the high sensitivity of the two analog scales which patients can use to determine their individual pain intensity proved to be much more sensitive. All three methods correlated statistically; the highest correlation coefficients were found between the analog scales VAS and the dolorimeter. Because the dolorimeter is clearly preferred to the other methods, especially by elderly patients, we came to the conclusion that the dolorimeter is less abstract than the VAS and more practical to handle.