As policy makers struggle to develop regulatory oversight models for nanotechnologies, there are important lessons that can be drawn from previous attempts to govern other emerging technologies. Five such lessons are the following: (1) public confidence and trust in a technology and its regulatory oversight is probably the most important factor for the commercial success of a technology; (2) regulation should avoid discriminating against particular technologies unless there is a scientifically based rationale for the disparate treatment; (3) regulatory systems need to be flexible and adaptive to rapidly changing technologies; (4) ethical and social concerns of the public about emerging technologies need to be expressly acknowledged and addressed in regulatory oversight; and (5) international harmonization of regulation may be beneficial in a rapidly globalizing world.