We report the case of an adult patient with thumb polydactyly. The pre-axial thumb is in a non-functional flexion, while the 1st thumb maintains normal function. X-ray of the hand reveals a “T” shape 1st metacarpus bone, giving origin to the pre-axial polydactyly. Although this variation is not specifically described in the Wassel classification, we classify it as a type V of the Rotterdam´s classification. Patient is managed surgically, using a dynamic incision for polydactyly amputation. The polydactyly thumb has no identifiable muscle/tendon structures responsible of this unique deformation. The procedure results in good post-operative evolution with aesthetic scaring, and integral thumb function.