Volumes of the thalamus and 4 thalamic substructures (i.e., anterior (AT), mediodorsal (MD), ventrolateral (VL), pulvinar (Pul)) were quantified using a novel automated segmentation algorithm in 18 individuals meeting criteria for Alcohol Use Disorders (AUD) and 28 healthy controls (Con). Multiple regressions considered contributions of diagnosis (i.e., Con vs. AUD), age, sex, and intracranial volume on substructural volumes. Volumes of AT, VL, and Pul were smaller with increasing age. Volumes of MD and Pul were affected by diagnosis: both were smaller in the AUD relative to the Con group. These results suggest that thalamic substructures have differential vulnerability to pathological processes.