Synchrotron small-angle X-ray scattering (SAXS) was used to analyze the structure of self-assembled autoxidized phospholipids in a very dilute solution of hexane. In addition, it was used to build a self-consistent model of the aggregates, taking into account their inner heterogeneities and polydispersity. The scattering intensity from a dilute mixture of different types of noninteracting components of the phospholipid system was represented as a linear combination of partial intensities from the components weighted by their volume fractions. Applying this approach the final model of the system was described as a mixture of polydisperse reverse micelles and aggregates with spherical and cylindrical shapes. Spherical aggregates were represented as hollow spheres with inner radius 0.7 nm (occupied by water or hexane) and outer radius 1.5 nm. Geometrical parameters of the aggregates did not change much during the oxidation process, while the ratio of reverse micelles and aggregates in solution varied. The amount of the reverse micelles increased from very low to about 80%, whereas the content of other aggregates constantly reduced. The analysis performed in this study helps one to better understand the processes of phospholipid oxidation, which may occur in biological membranes.