Hypoplasia and aplasia of the thumb constitute approximately 11% of congenital disorders of the upper extremity. Surgical treatment depends on type of disorder in Blauth classification used in our Department. Soft tissue procedures and pollicisations are performed most often. Microsurgical transplantation of interphalangeal joint from the toe is an alternative. This paper describes a case of microsurgical treatment in 20 years old patient with hypoplastic thumb. Two months after surgery the range of motion in transplanted joint was between 20 and 75 degrees.