A protein delivery system with a protein needle has been constructed. Green fluorescent protein (GFP) was genetically fused to a cell-penetrating protein needle. The construct is stable in buffer and cell culture medium. Internalization of the construct in HeLa cells and subsequent release of GFP from the needle was observed. The study provides a useful tool for intracellular protein delivery in an efficient manner and has potential for use in vitro and in vivo applications.