The authors analyzed the association between APOE epsilon4 genotype and clinical and MRI findings in 43 refractory temporal lobe epilepsy patients. The distribution of the alleles were normal. Ten patients (23%) had an APOE epsilon 4 allele and had an earlier onset of habitual seizures (with epsilon4 5 +/- 5 years; without epsilon4 15 +/- 10 years). Quantitative MRI findings were not influenced by the APOE epsilon4 genotype. APOE epsilon4 may shorten the latency between an initial injury and seizure onset.