The nascent nanotechnology revolution promises many benefits to humankind. An exciting and sometimes bewildering variety of new nanofabrication technologies and nanodevices based on electrical, optical, magnetic, mechanical, chemical and biological effects are reported almost daily. It is prudent to ask, however, how many of these breakthroughs will remain laboratory curiosities and how many will proceed to widespread industrialization. We argue that a metrology infrastructure has underpinned all industrial revolutions, and that this infrastructure is weak or nonexistent for many of the proposed nanosystems. More attention needs to be paid to metrology or progress will be derailed in a number of areas.