Investigation of the intrinsic relationship between crystallography and electronic properties may provide an avenue to unravel the photophysical aspects of semiconductor nanostructures. Since the 1980s, semiconducting materials at the nanoscale dimensions have been of immense scientific interest because of the unique quantum characteristics beyond a particular size limit. Prudent advances in the synthetic strategies of naked ZnO quantum dots have offered the opportunity to imbue the structure–property relationship of nanostructured systems. Seven size-specific ZnO nanospheres have been synthesized through alkaline hydrolysis of the precursor salt in the presence of alcohol in the reaction medium. The photoluminescence behavior of colloidal dispersion of ZnO nanoparticles has been studied as a function of excitation wavelength with a periodic interval of 10 nm in the range of 290–430 nm. It has been observed that changes in the excitation wavelength shift the emission spectrum in a regular manner independent of the size of ZnO particles under investigation. The empirical proposition in the framework of Kasha’s rule has been established as a milestone of spectroscopy, being validated in tens of thousands of fluorophore systems; meanwhile, although obscure, anomalous cases have also been observed both in molecular and nanoscale systems. Crystallographic analysis has shown that there occurs a structural transition that determines the localization of electronic energy levels in the experimental size range of the ZnO particles. Therefore, the salient feature of physical significance is that crystallographic transition appears to exhibit the excitation wavelength-dependent shift of the photoluminescence maximum and is therefore the violation of Kasha’s rule for the ZnO quantum dots.