Modern material science is paying more attention on the development of nanomaterials for superior properties in various fields of applications like mechanical, thermal, electronic, bio-medical etc. For such applications, determination of nanoparticle sizes along with their distribution is important for attaining the desired properties. Particle sizes along with the crystallite sizes of oxides, non-oxides and metallic nanopowders produced by different processes can be determined by different techniques which includes x-ray diffraction/neutron diffraction (XRD/ND), transmission electron microscopy/field emission scanning electron microscopy (TEM/FESEM), Brunauer-Emmett-Teller (BET) surface area method, small angle neutron scattering (SNAS), dynamic light scattering (DLS), static light scattering (SLS), etc. For average nano-metric particle size determination, DLS is the most frequently used technique that gives a distribution that approximates the exact binomial distribution of large numbers of nanoparticulates with varying particle size under investigation (Gaussian distribution). However, the other techniques mainly give either localized distribution of the particles under observation or the distribution derived from type II isotherm. In this investigation, nano-alumina powder produced by the electrical explosion of wire technique (EEW) is used for comparative evaluation of particle size analysis by DLS measurement technique for nanoparticles vis-a-vis to other techniques like XRD (for crystallite size), FESEM, BET, and TEM. The superiority of the DLS technique has been discussed in details with respect to the unique features of its Gaussian distribution nature.