Lead (Pb) is a widespread toxic metal found in the environment with potential danger to human health. It is used in the manufacture of batteries, metal products, paints and other domestic substances. This study investigated the effect of aqueous seed extract of Nigella sativa on leadinduced cerebral cortex toxicity in Long Evan's rats. Twenty five Long Evans rats divided into five groups of five animals were used for the study. Group I received Distilled water, group II received aqueous seed extract of Nigella sativa (1000mg/kg), group III received lead (60mg/kg), group IV received lead (60mg/kg) followed by aqueous seed extract of Nigella sativa (1000mg/kg) and group V received lead (60mg/kg) followed by aqueous seed extract of Nigella sativa (500mg/kg) via oral intubation. Elevated Plus Maze (EPM) was used to study anxiety-like behaviour. Activities on the elevated plus maze showed that there was no statistically significant decreased rate of anxiety across the groups (P>0.05). The histology of the cerebral cortex of long Evans rats in group IV that received Lead (60 mg/kg) followed by aqueous seed extract of Nigella sativa (1000mg/kg) showed mild neuronal damage while the histology of group V animals that received lead (60mg/kg) followed by aqueous seed extract of Nigella sativa (500mg/kg) showed severe neuronal damage. It can be concluded that aqueous seed extract of Nigella sativa at high dose have more therapeutic effect than at low dose.