Abstract: An anaerobic adhesive composition activatable by ultraviolet or visible radiation is disclosed which forms strong bonds with lapped surfaces and which is comprised of (a) an anaerobically polymerizable acrylate ester monomer, (b) a compound which decomposes upon exposure to ultraviolet or visible light radiation to release a strong acid, (c) a peroxy free radical initiator capable of initiating the polymerization of the monomer upon substantial exclusion of oxygen and (d) an activator of anaerobic polymerization which, in the presence of a strong acid, reacts with the peroxide initiator to produce free radicals to catalyze the anaerobic polymerization of the monomer.