Electrically conductive monolayers of polypyrroles have been synthesized at the air-water interface of a Langmuir-Blodgett film balance. This was accomplished by spreading a mixture of pyrrole monomer and a surface-active pyrrole derivative (3-octadecyl pyrrole) onto a subphase containing an oxidizing aqueous solution of FeCl 3. The resultant electrically conductive films can be subsequently compressed into a condensed monolayer in which they exhibit the surface pressure- area characteristics of the 3-octadecyl pyrrole in a slightly expanded state. It has also been found that neither the pyrrole nor the 3-octadecyl pyrrole will react at the air- water interface to produce electrically conductive materials under the conditions used to polymerize the mixture. In other words, electrically conductive monolayers can only be produced from spreading solutions containing both the surface-active pyrrole and pyrrole monomer. Preliminary IR analysis indicates that the newly formed polymer monolayer comprises both pyrrole and alkyl pyrrole units.