A 19-year-old man was abruptly awakened during the night by the painful bite of a female sac spider, later identified as Chiracanthium mildei. An erythematous urticarial plaque formed immediately. Later, punctate macules appeared, and the bite site became indurated. The clinical response was similar to those reported following bites by Chiracanthium spiders in Japan, Australia, Europe, Massachusetts, Georgia, Indiana, California, and Hawaii [USA]. The necrotic lesions associated with some of those bites did not occur in this case. This is the first reported case of C. mildei bite in Connecticut [USA].