The widespread use of pharmaceutical drugs like carvedilol (CAR) has raised concerns regarding antibiotic resistance, environmental pollution, and potential health risks. This study addresses these issues by employing advanced pristine nanomaterials, including ZnO and Cu3SnS4 to intricately engineer ZnO-Cu3SnS4 nanocomposite (NCs). These NCs are designed for enhanced photocatalytic degradation of CAR. Detailed characterization through SEM, and elemental mapping reveals the nanocluster morphology, amorphous nature, proper deposition distribution, and heterojunction formation. XRD studies confirm the purity of the synthesized materials, while XPS validate their chemical states and bonding nature. BET and BHJ analyses demonstrate the enhanced surface area and mesoporous nature of the NCs respectively. UV-visible DRS illustrates successful visible-light sensitization of the ZnO-Cu3SnS4 NCs with a bandgap of 2.96 eV. Photoluminescence studies indicate reduced charge carrier recombination in the NCs. .OH being the dominant radical involved in photodegradation. The photocatalytic degradation of CAR by ZnO-Cu3SnS4 NCs achieves a remarkable degradation efficiency of 98% under optimal condition. These NCs also show outstanding stability across several cycles and remain to function in the presence of ions. Finally, GC-MS analysis suggests the potential CAR degradation routes that result in less hazardous end products. In conclusion, the present research highlights the potential of ZnO-Cu3SnS4 NCs for efficient wastewater treatment and highlights their capacity to tackle issues related to pharmaceutical drug contamination.