The synthesis of polypeptides by N-carboxyanhydride (NCA) photopolymerization is demonstrated. The active initiator cyclohexylamine was produced in situ by the UV-induced breakdown of photoamine generators. Real-time FTIR and MALDI-ToF-MS analyses provide clear evidence for the proposed photoinitiation mechanism as well as the attachment of the active initiator to the polypeptide chain. NCA photopolymerization generates new possibilities for designing polypeptides both in solution and on surfaces.