The scanning force microscope uses a sharp tip mounted on a flexible cantilever to touch and create images of a surface. During the past year, great progress has been made in the applications of SFM to imaging biological specimens. This progress has been made possible by advances in three areas: improved tip fabrication, development of better deposition methods; and control of sample environment. At present, SFM can reliably image most types of biological molecules at ~ 50-100 Å resolution, depending on the system studied. The main technical advances of the past year, which often took place in connection with the imaging of nucleic acids and nucleoprotein assemblies, are reviewed. Potential solutions to present technical limitations and promising new developments now underway are also discussed. © 1993 Current Biology Ltd.