ABSTRACT: BACKGROUND: Accessory ADM was first reported in 1868 although muscular, vascular and nervous variations of the hypothenar eminence are rare, contrary to anomalous muscles in the wrist which are relatively common. CASE PRESENTATION: This case report presents a bilateral variation of an accessory abductor digiti minimi muscle in a male specimen. Ulnar artery and ulnar nerves were taken into account regarding their position and trajectory related to this variation. CONCLUSION: Muscle size may be an important factor in considering whether a variation is able to produce neurovascular compression and clinical implications.