Acanthus montanus aqueous extract (AM) is a traditional treatment for pain, female infertility and threatened abortion with dosage schedule depending on the ailment. AM was evaluated for subacute toxicity. Female Wistar rats, 6/group, took oral doses of AM at 0, 125, 250, 500 and 1000 mg/kg/day for 30 days. Hypercreatinine was observed on day 30 but not glucose, transaminases, total proteins, hematological parameters, oxidative stress markers, gross and histological changes on liver, lungs and heart. However, kidneys of 1000 mg/kg/day group had crystals resulting in glomerulosclerosis. In conclusion present results suggest that, AM lacks effects on hematological, some biochemical; and oxidative stress markers but possesses nephrotoxic and hypecreatinemic effects at a dose > 500m/kg/day which is below the nominal human value.