Cr doped polyanthranilic acid (Cr PANA) has been used as a molecular precursor of Cr2O3 nanoparticles. Potassium dichromate acted as an oxidant and a dopant in Cr PANA synthesis. The spectral, optical and thermal properties of the precursor have been described. Thermogravimetric Analysis (TGA) and differential scanning calorimetric (DSC) were used to clarify the thermal stability of Cr PANA. The optical band gap (Eg) measurements indicated that Cr PANA has wider optical band than the pure PANA. Calcination of Cr PANA at 600 °C produced Eskolaite (Cr2O3) nanoparticles. The obtained nanoparticles have been characterized by XRD and TEM. The average size of the nanoparticles was found to be 70 nm. The measured optical band gap of Eskolaite nanoparticles is 0.35 eV wider than the bulk.