The utilization of shock waves plays a pivotal role in the advancement of multiple scientific domains like aerospace, defense, geology, environment, medicine and many more. They serve as essential tools in scientific investigations, enabling the exploration of material behavior under extreme conditions, viz. elevated pressure and temperature. The present study is specifically dedicated to scrutinizing the repercussions of shock waves on an L-ascorbic acid single crystal, to which they were intentionally applied to assess their influence on structural, optical and third-order nonlinearity properties. Powder X-ray diffraction analysis unveiled a discernible overall enhancement in the crystalline quality of the grown crystal following exposure to shock waves. This observation was consistently corroborated by high-resolution X-ray diffraction data, particularly on the (200) crystallographic planes. Furthermore, the optical transmittance of the crystal exhibited a notable increase upon the application of shock waves, while the material's band gap remained unaffected. In parallel, the third-order nonlinearity of the crystal was found to undergo a significant augmentation as a consequence of the shock treatment, as confirmed through Z-scan measurements. These empirical findings unequivocally demonstrate the substantial enhancement in the structural, optical and nonlinear properties of the grown crystal when subjected to shock waves, rendering it well suited for nonlinear optical applications.