To study cognitive function and its relationship with magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in patients with temporal lobe epilepsy. Methods: Thirty-six patient cases of temporal lobe epilepsy were selected from our hospital as the epilepsy group and 36 healthy cases were selected as the control group. The Mini-Mental State Examination (MMSE) and Wechsler Adult Intelligence Scale (WAIS) were applied to assess cognitive function of the two groups, and MRI and DTI were performed. The values of mean diffusion and fractional anisotropy on different regions of interest were compared between the two groups, and the relationship between cognitive function imaging results was analyzed. Results: The MMSE and WAIS scores of the epilepsy group were lower than those of the control group (all P<0.05). The values of fractional anisotropy of the left and right thalamus and the posterior limb of the left and right internal capsule in the study group were lower than those of the control group (all P<0.05). Results of correlation analysis showed that the mean diffusion of the left posterior limb of the internal capsule, left genu, and left thalamus showed a significant negative correlation with the WAIS score (all P<0.05). The fractional anisotropy of the left anterior limb and the left occipital lobe showed a significant positive correlation with the MMSE score (all P<0.05). The fractional anisotropy of the left occipital lobe showed a significant positive correlation with performance IQ (P< 0.05). The fractional anisotropy of the right occipital lobe showed a significant positive correlation with full IQ, verbal IQ, and performance IQ (all P<0.05). Conclusion: Patients with temporal lobe epilepsy possess a certain level of cognitive dysfunction. Examination by MRI and DTI can effectively detect the damaged brain region and evaluate the extent of the damage