This study investigates the removal of paracetamol (PCM) from pharmaceutical waste using zinc oxide nanoparticles (OB-ZnO NPs) synthesized from *Ocimum basilicum* (OB) plant waste. The synthesized OB-ZnO NPs were characterized using various techniques, including X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), Zetasizer, thermogravimetry-differential thermal analysis (TGA-DTA), and UV-vis spectroscopy. The crystal structure of the NPs was found to be hexagonal wurtzite with a particle size of 30.39 nm, a surface area of 13.826 m²/g, and a pore volume of 0.0475 cm³/g. The zeta potential of the NPs was −22.1 mV, and they showed a mass loss of 33% at about 750 °C, indicating their durability at high temperatures. Kinetic and isotherm models were used to determine the most suitable model for PCM removal, with the Elovich model showing an R² value of 0.989 and the Redlich-Peterson model showing an R² value of 0.999. The adsorption efficiency of PCM was 23 mg/g, demonstrating the potential of OB-ZnO NPs for removing pharmaceutical wastes.This study investigates the removal of paracetamol (PCM) from pharmaceutical waste using zinc oxide nanoparticles (OB-ZnO NPs) synthesized from *Ocimum basilicum* (OB) plant waste. The synthesized OB-ZnO NPs were characterized using various techniques, including X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), Zetasizer, thermogravimetry-differential thermal analysis (TGA-DTA), and UV-vis spectroscopy. The crystal structure of the NPs was found to be hexagonal wurtzite with a particle size of 30.39 nm, a surface area of 13.826 m²/g, and a pore volume of 0.0475 cm³/g. The zeta potential of the NPs was −22.1 mV, and they showed a mass loss of 33% at about 750 °C, indicating their durability at high temperatures. Kinetic and isotherm models were used to determine the most suitable model for PCM removal, with the Elovich model showing an R² value of 0.989 and the Redlich-Peterson model showing an R² value of 0.999. The adsorption efficiency of PCM was 23 mg/g, demonstrating the potential of OB-ZnO NPs for removing pharmaceutical wastes.