The study reports the biosynthesis of Nickel oxide nanorods (NiO NRs), using Phoenix dactylifera (Dates) extract, a safe, environment friendly and cost effective method. X-ray diffraction analysis confirmed the high crystallinity with face centered cubic phase and HR- TEM (high resolution transmission microscopy) studies confirmed the existence of nanorod like morphology with average particle size of 32 nm. Optical study using UV–Vis spectroscopy revealed a sharp band edge with an energy band gap of 3.62eV. Photoluminescense spectroscopy showed strong defect derived emission from UV and visible region while magnetic measurements indicated a superparamagnetic behavior. The as-synthesized NiO NRs were examined for cytotoxic activity against A549 cell lines, antibacterial activity and photocatalytic degradation of 4-chlorophenol (4-CP). NiO NRs exhibited strong toxicity over A549 cell culture by imparting severe damage to cell functions, a superior antibacterial activity against gram positive than gram negative bacterial strains, as well as competent photocatalyst by mineralizing 4-CP under UV light. Thus NiO NRs prepared by green protocol using Phoenix dactylifera extract, can be considered very promising for biomedical and environmental applications. © 2019 Elsevier B.V.