In this study, nonionic surfactants were used in order to enhance the solubilization of sulfur compounds contained in the crude oil. There different types of nonionic surfactants were used and the solubilized sulfur contents were measured by X-ray sulfur spectrometer. It was observed that the longer the hydrophobic chain length of the surfactant molecule in a set of homologs, the higher solubilizing capacity of a nonionic surfactant. The solubilization of bulky sulfur compounds was found to be greatly affected by the packing density of surfactant aggregates. As crude oil contents were increased, partitioning of nonionic surfactants into the oil phase was observed, especially for the hydrophobic ones among the surfactants used for this study.