Abstract Epilepsy is the most common serious neurological condition affecting 1 to 2 % of world population. Despite extensive progress, there are still many unanswered questions about factors inducing epilepsy. Therefore, this work was carried out in an attempt to study the effect of nitric oxide (NO) modulation on the development of epilepsy. Rats were divided into the following equal groups (8 rats each) according to their treatment; 1. Control non- treated; 2. Pilocarpine-treated; 3. Pilocarpine + Diazepam treated; 4. Pilocarpine + L-arginine (NO precursor)-treated groups. Twenty-four hours' rat observation and biochemical analysis of brain homogenates and serum showed that Pilocarpine induced seizures in all rats with high lethality associated with increased brain excitatory transmitter; glutamate, Gamma aminobutyric acid (GABA), malondialdehyde (MDA; oxidative stress marker) and NO levels, along with increased serum level of inflammatory mediator; tumor necrosis factor (TNF-α). Complete protection was observed with Diazepam without reversal of Pilocarpine- induced brain excitatory transmitters changes apart from a significantly higher GABA levels along with reduced brain NO and MDA levels and serum levels of TNF-α. On the other hand, L-arginine pretreatment aggravated the condition and accelerated the induction of seizures with high lethality reaching 100% after 24hrs. Biochemical and tissue parameters showed significantly high serum TNF-α levels as well as significantly high brain Glutamate, NO, MDA along with significantly low brain GABA levels. In conclusion, although the role of NO in the pathophysiology of epilepsy is controversial, our results showed that L-arginine; the NO precursor proved to be proepileptic, and thus opening the way for a new strategy of antiepileptic management.