This work aims to explore the characteristics of TiO2 NPs green-synthesized via an environmentally friendly method using oil palm (Elaeis guineensis) leaf extract as a green medium and capping agent by utilizing titanium tetra isopropoxide (TTIP) as precursor. The oil palm leaves were extracted with different solvent concentration variations. The natural extract was characterized using liquid chromatography-mass spectroscopy (LC-MS) and infrared spectroscopy for active chemical contents and functional groups. The obtained TiO2 NPs were also characterized using infrared spectroscopy (FTIR) for the functional groups, ultraviolet spectroscopy (UV-DRS) for the optical characteristics, and X-ray diffraction (XRD) for the phase formation and crystallographic properties. More sophisticated equipment of field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (FESEM/EDX) and Raman spectroscopy were employed to reveal the characteristics of the obtained TiO2 NPs. The results from X-ray diffraction showed that the obtained TiO2 NPs are in pure anatase crystal structure. There is also a trend that the bandgap energy of TiO2 NPs reduces with the use of oil palm leaves extract as a green medium. It is confirmed that the green medium affects the optical characteristics of the synthesized TiO2 NPs by reducing the bandgap energy from 3.2 eV for commercial and the one synthesized using ethanol only to 3.12 eV by using the green medium of oil palm leaves extract. These findings will provide insight for more novel, environmentally friendly nanomaterials synthesis methods. © 2026, University of Baghdad. All rights reserved.