Preliminary studies on the suitability of some organic acids and amines, separately and in combination with each other, as photoinitiators for the polymerization of methyl methacrylate were made. Combinations of maleic acid or phthalic acid with any of the tertiary amines-triethyl amine, demethyl aniline, and diethylanilineproved to be interesting photoinitiator systems in view of the fact that the initiator components in each combination were ineffective as initiators when used separately. The rate of photopolymerization in each of the above acid-amine combination system was much enhanced and the respective inhibition period largely reduced when benzophenone was used as the photoinitiator. Aliphatic diamine or polyamines such as ethylene diamine, diethylene triamine, and triethylene tetramine, were ineffective as photoinitiators when used alone or in combination with maleic acid, but became effective. © 1983, Taylor & Francis Group, LLC. All rights reserved.