Photoaddition reactions of pyrroles (2-4) and indoles (5-8) to N-methyl-2-pyridone (1) have been investigated. The reaction occurred primarily by way of addition of the C2-H bond of the pyrrole ring and the C3-H bond of the indole ring to the pyridone nucleus, yielding 4-substituted 3, 4-dihydro-1-methylpyridin-2(1H)-ones (9 from pyrrole; 13 and 17 from indoles) and 6-substituted 3, 6-dihydro-1-methylpyridin-2(1H)-ones (10 from pyrrole; 14 and 18 from indoles). The presence of a methyl group(s) at the reactive site(s) of pyrrole and indole resulted in the formation of the products arising from the addition of the C3-H bond of the pyrrole ring, and the N1-H, C2-H and C6-H bonds of the indole ring. N-Methylpyrrole (4) and N-methylindole (8) did not give any detectable amount of the addition product.