Vitamin A and its derivatives have recently reported to be implicated in synaptic plasticity. The possible effect of vitamin A and its precursor, ?-carotene, on seizure acquisition was tested in PTZ kindling model of epilepsy. Vitamin A and ?-carotene were tested for their ability to 1) suppress seizures (clonic and tonic) and lethality induced by PTZ in PTZ-kindled mice (anticonvulsant effect) and 2) attenuate the development of sensitization to convulsive and lethal effects of PTZ in kindled mice (anti-epileptogenic effect) when given as a pretreatment prior to each PTZ injection during kindling acquisition. Diazepam was used as positive control group. All these drugs showed anti-epileptogenic effects against PTZ-induced tonic seizures and lethality. Vitamin A and ?-carotene had no effect on clonic seizures induced by PTZ in kindled mice. It can be concluded that vitamin A and ?-carotene possess anti-epileptogenic activity. Retinoids appear to be valuable for development of a new class of anticonvulsant drugs.