The micro- and nanostructured phase behavior of non-woven hybrid electrospun fibers of Polycaprolactone (PCL-f), Polycaprolactone/α-Alumina (PCL/AA) and Polycaprolactone/Hydroxyapatite (PCL/HA) were elucidated. Nanoparticles of Hydroxyapatite featured 7-20 nm while α-Alumina was 500 nm in average size. Analysis by Transmission Electron Microscopy (TEM), Small-Angle Light Scattering (SALS), Polarized Optical Microscopy (POM) and Differential Scanning Calorimetry (DSC) enabled us to suggest a simple structural model for the series of hybrid fibers. PCL with a molecular weight of 70,000 g/mol was dissolved in chloroform. POM exhibited qualitative birefringent regions for all samples at the microscale level. Furthermore, polarized light distinguished between amorphous and micro-ordered structures along the fibers. On the other hand, SALS patterns suggested a needle-like morphology for all fibers. The influence of both, Hydroxyapatite and α-Alumina, was apparent in the SALS patterns of the PCL semicrystalline phase. Thermal analysis by DSC showed that the crystalline phase of PCL was disrupted by the presence of the inorganic nanoparticles. TEM micrographs showed that Hydroxyapatite and α-Alumina nanoparticles were embedded along the structure of PCL microfibers.