Structure analysis of multifunctional nanoparticles could be a complex process. In this paper, we demonstrate the step-by-step techniques used for identifying the structure of the CoFe-Fe3O4 nanoparticles, which are composed of similar to4-mn CoFe cores and covered with similar to3-nm Fe3O4 polynanocrystallites. The techniques demonstrated are general and can be adopted for analysis of any nanoparticles of interest in physical chemistry.