Tissue expansion is a well-established technique for the management of soft tissue deficiencies. In congenital hand surgery the construction of an adequate first web is paramount. We used tissue expansion in four hands in three patients with complete complex syndactyly of the first web space. Two of these patients had Apert's syndrome and the other an isolated mitten hand anomaly. The expander is preferably placed early in life so that first web construction is completed in the first year. Tissue expander ports are left exposed. There have been no infections, flap or expander loss in our series.