The following list of hymenopterous parasites of Choristoneura pinus Free. is based on an analysis of two collections that the writer recently received through the kindness of Dr. T. N. Freeman. The first collection consisted of 116 mature larvae and pupae of C. pinus taken by Dr. Freeman at Normandale (Norfolk Co.), Ont., early in July, 1951, in a plantation of Pinus banksiana Lamb. Rearings from this lot, at Ottawa, by Dr. Freeman and the writer yielded 48 moths and 41 specimens of parasites, the latter comprising 10 species. There was a pupal mortality of 27 specimens. The second collection consisted of 75 adult parasites that were reared at Ottawa by Dr. Freeman from a lot of 456 pupae of C. pinus taken by Mr. V. Hildahl at Beauséjour, Man., during July, 1951, on P. banksiana. There were five species of parasites in this collection, three of which are not represented in the Normandale material.