Catharanthus roseus leaf extract has potential efficien-cy for the formation of biosynthesized zinc oxide (ZnO) nanoparticles against dye degradation with various time intervals. The leaves of C. roseus were utilized as reducing agent for the formation of metal precursors into metal oxide nanoparticles. C. roseus-mediated ZnO nanoparticles were confirmed by vari-ous analytical techniques such as UV-Vis, FT-IR, XRD and morphological studies by SEM and TEM. Results show that green synthesized ZnO nanoparti-cles are directly proportional to reaction time. The phytoconstituents present in leaf extract of C. roseus play a major role in ZnO nanoparticles formation by acting as a reducing agent.