A 1-year arbovirus study was conducted at The Wedge Plantation located in coastal South Carolina to determine the occurrence and level of arbovirus activity in mosquito species inhabiting the site. Mosquito species composition and temporal abundance were also determined. A total of 45,051 mosquitoes representing 27 species in 9 genera was collected and identified during 130 trap-nights between August, 1997, and July, 1998. The most abundant species was Culex salinarius (n = 20,954) followed by Ochlerotatus taeniorhynchus (n = 12,185). Eastern equine encephalomyelitis virus (EEE) was isolated from 2 pools collected in August, 1997; one pool of Oc. taeniorhynchus (minimum infection rate [MIR] = 0.6/1,000) and a second of Culiseta melanura (MIR = 3.8/1,000). This report represents the first record of an EEE isolation from Oc. taeniorhynchus and Cs. melanura in South Carolina.