In this study, I provide the first description of mating behavior in the field for the genus Castianeira Keyserling, 1879 (Araneae: Corinnidae). Females have been observed building intricate mounds over their egg sacs; this study describes mating behavior while the female was building a mound—suggesting that females may have more than one clutch of offspring during the mating season or that she may store sperm for the next mating season. Analysis of my field footage and observational data revealed a simple mating behavior with little pre-or post-copulatory interaction. I compared my observations with laboratory observations by Montgomery (1909) of Castianeira descripta (Hentz, 1847) and Castianeira longipalpa (Hentz, 1847). The mating behaviors are similar in length but the sequence and duration of coupling differed. These observations create a starting point for better researching courtship and mating behavior of this spider, the number of egg sacs produced during a season, as well as the role of mound-making in the reproduction process.