Of 603 birds collected at Wateree, South Carolina, 22.7% were infected with one or more blood parasites. The most prevalent infection was with Haemoproteus sp. followed by Plasmodium sp., microfilaria, Leucocytozoon sp., and Trypanosoma sp. The blood parasites of birds in South Carolina have been studied by Hart (1949) and by Hunninen and Young (1950). Hart examined a total of 323 English sparrows and 64 various other birds from 1946 to 1947. Hunninen and Young examined 737 birds collected on the grounds of the State Hospital at Columbia, South Carolina from 1947 to 1949. In the present investigation, birds were collected as part of a program to investigate the incidence of Plasmodium and virus infections in birds and mosquitoes in a selected area of South Carolina. Reported here are the results of this study in regard to prevalence of blood parasites in birds collected during a period of approximately 11 months. MATERIALS AND METHODS The study area selected was in the southeastern corner of Richland County, South Carolina. The area was approximately 6 miles long, running along U. S. Highway 601 from the Southern Railroad crossing in Wateree, South Carolina to the Wateree River. Collections were made on both sides of the road in an area approximately 2 miles wide. The area consisted of extensive pine plantings with intermixed areas of freshwater swamp. At the Wateree end of the area was located a farm on which were raised chickens, cattle, and horses. Birds were collected in Japanese nylon mist nets or were shot, the latter proving to be the most effective method in the very dense areas and for several species of birds such as woodpeckers. Blood smears were made from the blood samples collected by cardiac puncture, the latter being used for purposes other than those discussed in this paper. Two blood slides were made from each bird. The slides were air dried, fixed with methyl alcohol, and stained with Giemsa. The slides were studied under low power (100 X) for the detecReceived for publication 20 January 1966. * Address: Assistant Chief, Laboratory of Parasite Chemotherapy, NIAID, NIH, Bethesda, Maryland. t Address: State Entomologist, South Carolina Department of Health, Columbia, South Carolina. tion of the microfilariae and under oil immersion (970 X) for the detection of the other parasites. A minimum of 100 fields were examined before a smear was considered negative. The presence of Plasmodium sp., Leucocytozoon sp., Haemoproteuis sp., Trypanosoma sp., and microfilaria was recorded. The collection periods were from 5 June 1962 to 14 November 1962, and from 12 March 1963 to 16 April 1963.