Some sex differences have been detected in driving while impaired by alcohol (DWI) offenders. However, understanding of the key factors contributing to DWI among male and female drivers remains elusive, limiting development of targeted interventions. Sex-based neurocognitive analyses could provide the much-needed insight. We examined whether male DWI offenders show cortical thickness anomalies that differ from those in female DWI offenders, when compared to their respective controls. Moderating role of sex and alcohol use on DWI status was also investigated. Sixty-one DWI offenders (29 male; 32 female) and 58 controls (29 male; 29 female) completed an anatomical brain scan and assessments on other relevant characteristics. Only male DWI offenders had reduced cortical thickness in the right dorsal posterior cingulate cortex (PCC), a region involved in cognitive control. Lower cortical thickness was associated with increased odds of DWI status only among males who have not engaged in very hazardous pattern of alcohol misuse in the previous 12 months. Thus, for these male DWI drivers, interventions that could impact PCC could be most advantageous. Continued multidimensional sex analysis of the neural characteristics of male and female DWI offenders is warranted.