In this paper, a simple and facile surfactant assisted combustion synthesis is reported for the ZnO nanoparticles. The synthesis of ZnO-NPs has been done with the assistance of non-ionic surfactant TWEEN 80. The effect of fuel variations and comparative study of fuel urea and glycine have been studied by using characterization techniques like X-ray diffraction (XRD), transmission electron microscope (TEM) and particle size analyzer. From XRD, it indicates the presence of hexagonal wurtzite structure for ZnO-NPs. Using X-ray broadening, crystallite sizes and lattice strain on the peak broadening of ZnO-NPs were studied by using Williamson-Hall (W-H) analysis and size-strain plot. Strain, stress and energy density parameters were calculated for the XRD peaks of all the samples using (UDM), uniform stress deformation model (USDM), uniform deformation energy density model (UDEDM) and by the size-strain plot method (SSP). The results of mean particle size showed an inter correlation with W-H analysis, SSP, particle analyzer and TEM results.