Although avascular necrosis of the hallucal sesamoid has not been frequently addressed in the literature, it should be considered in the differential diagnosis of persistent forefoot pain. We experienced 3 cases of avascular necrosis of the hallucal sesamoid with sclerosis of the sesamoid bone on radiograghs and computed tomograghy images. T1 and T2-weighted MRI images in 2 patients showed low signal intensity in the sesamoid bone, which suggested osteonecrosis and confirmed by histology. We report 3 cases of avascular necrosis of sesamoid with a review of the literature.