Sulfur compounds are among the components of most crude oils and their products. When burning diesel fuel, two main pollutants are discharged into the atmosphere. Particulate matter (PM) is directly related to the amount of the sulfur content in the diesel fuel. Nitrogen oxides in the exhaust gases are a direct function of the engine design and operating conditions. It is therefore important to monitor the sulfur content of the diesel fuel. In this dissertation, its measurement quality and traceability were determined when comparing the results obtained by six laboratories, which are operating in the state of Rio de Janeiro. The x-ray fluorescence (XRF) sulfur measurement technique, as described by the ASTM D2622-98 standard, was used by all the laboratories in this intercomparison program, which was conducted following the ABNT ISO/IEC 17025 standard. The objective of this work is thus to perform a metrological evaluation of the sulfur content in the diesel fuel through the x-ray fluorescence technique. Working range, linearity, resolution, accuracy, repeatability, reproducibility and measurement uncertainty are the parameters used for the performance evaluation, as referred to the 95,45 percent confidence level. The metrological evaluation showed that the use of a certified reference material, together with the performance evaluation parameters, produced results, which were compatible with the used methodology. This intercomparison program also helped the laboratories to identify nonpreviously detected measurement errors, thus improving the measurement quality and reliability in the analytical technique.