(VSP) process conducted with variable shot peening conditions. The variable parameters of the process were: ball material (100Cr6 and HS18-0-1) and vibratory shot peening time (t=1 min and t=15 min). Surface topography, surface roughness (3D parameters), surface microhardness, and residual stress were examined before and after the shot peening process. A multi-factor ANOVA analysis was performed for the surface roughness parameter Ra. For the C45 steel samples, the use of vibratory shot peening leads to increased surface roughness compared to that before shot peening. The 3D surface roughness parameters of 100Cr6 steel are lower after the vibratory shot peening process than before VSP. The effect of vibratory shot peening is increased microhardness, which is greater for the C45 grade of steel than for 100Cr6. After VSP, compressive residual stresses occur in the surface layer. The shot peening process conducted with the 100Cr6 shot produces surfaces with lower surface roughness than that obtained after shot peening with the HS18-0-1 shot, whatever the workpiece material and the time t. Regarding the physical properties of the surface layer (microhardness and residual stress), better results (a greater increase in the microhardness ΔHV and a higher absolute value of the compressive residual stress σ) were produced by the shot peening process conducted with HS18-0-1 balls.