This paper reported the toxic and teratogenic effects of water leaf extract of Momordica charantia in developing embryos of Danio rerio. The mortality, hatchability, delayed development and morphological abnormalities of extract treated embryos were determined. After 36 and 48 h of exposure, 100% mortality was observed in embryos at 3% of extract. The toxic effects of the extract were dependent on extract concentration and time of exposure. Embryos exposed to 0.1%, or higher concentrations showed delayed development. Control embryos showed 100% hatchability while no hatching was observed in embryo exposed at 0.1% or higher concentrations. Treated embryos had bent back, scoliosis, edema in the yolk sac, bent tail tip as manifestations of teratogenic effects of the plant extract.