The efficacy of NiO nanoparticles dispersed on a nanoporous carbon matrix (NiO/NPC) for microcystine-LR degradation in aqueous media is reported. The NiO/NPC catalyst was characterized by porosimetry, scanning electron microscopy, elemental analysis, powder X-ray diffraction, and X-ray photoelectron spectroscopy, and applied to the oxidative degradation of microcystine-LR contaminated water in the presence of hydrogen peroxide as a function of pH under ambient conditions. Optimal MC-LR removal efficiency was 86% at neutral pH catalyzed by this heterogeneous Fenton-like (NiO/NPC with H2O2) process, which has the added benefit of avoiding secondary metal pollution during microcystine-LR degradation. NiO/NPC represents an earth abundant catalyst for generating hydroxyl radicals to facilitate environmental depollution of organic pollutants from wastewater