We aimed to investigate the potential anticonvulsant effect of green synthetized selenium nanoparticles (SeNPs) using Syzygium aromaticum extract (SAE) (SAE-SeNPs) against epileptic seizures and cortical damage induced by pentylenetetrazole (PTZ) injection in rats and its mechanism. A total of 84 rats were divided into six groups; control, PTZ-exposed group, SAE + PTZ-treated group, sodium selenite (Na2SeO3) + PTZ-treated group, SAE-SeNPs + PTZ-treated group, and diazepam + PTZ-treated group. SAE-SeNPs significantly increase (p < 0.05) the latency time to seizures and reduce both the seizure duration and death rate, which were enhanced by the PTZ injection. SAE-SeNPs counteracted the PTZ-induced changes in the oxidants and antioxidants. Furthermore, SAE-SeNPs significantly restored (p < 0.05) the pro-inflammatory cytokines (interleukin-1β, interleukin-6, and tumor necrosis factor-α) to their normal levels and suppressed the activity of the glial fibrillary acidic protein showing their inhibitory effect on the epilepsy-associated inflammation. In addition, SAE-SeNPs significantly reduced (p < 0.05) PTZ-induced cortical cell apoptosis, as revealed by a reduction in the pro-apoptotic Bax and caspase-3 levels, and an elevation of the anti-apoptotic Bcl-2 level. Moreover, SAE-SeNPs significantly modulate (p < 0.05) the PTZ-induced changes in the neurotransmitter norepinephrine level and acetylcholinesterase enzymatic activity. These data concluded the anticonvulsant activity of SAE-SeNPs via their antioxidant, anti-inflammatory, and anti-apoptotic effects, along with their ability to modulate neurotransmitters.