To investigate the MRI features and the diagnostic value of posterior reversible encephalopathy syndrome (PRES) caused by pregnancy-induced hypertension (PIH). Methods: Clinical and MRI data of 20 cases of PIH were retrospectively reviewed. All cases were examined by MRI scanning and diffusion weighted imaging (DWI) before drug therapy. Results: There were 9 cases with PRES (45%) and 11 cases without PRES. MRI revealed 30 lesions in the PRES group: 12 in the occipital lobe, 3 in the corpus callosum, 5 in the parietal lobe centrum semiovale, 5 in the temporal lobe, and 3 in the frontal lobe. Lesion location involved sub-cortical white matter and neighboring portions of the cortex. Lesions were mildly hypointense on T1WI and mildly hyperintense on T2WI and T2WI/flair. Lesions were mildly hyperintense on DWI and hypointense on apparent diffusion coefficient (ADC). T2WI/flair detected the highest number of lesions. Two cases were only able to be clearly imaged on the DWI sequence. Conclusion: MRI features of PRES caused by PIH display certain characteristics; DWI combined with T2WI/flair can detect more lesions.