The mahogany shoot borer Hypsipyla grandella (Zeller) is one of the worst neotropical forest pests. Currently there is no control method that effectively reduces levels of infestation to an economically acceptable threshold. Basic knowledge on the sexual behavior of this pest is required to develop control methods. However, so far reproduction in this species has only been achieved in captivity and studied using outdoor mating cages. Here we describe for the first time, as far as we know, the precopulatory and copulatory behavior of H. grandella under controlled conditions. We found males and females performed a short and long wing-fanning behavior. Furthermore, we evaluated each behavior at three different sex ratios (3♂:1♀, 2♂:2♀, and 1♂:3♀), and studied the effect of male and female adult size on copulatory success. We observed 50% of copulations in the equal sex ratio, but found no significant effect of male or female size on the probability of mating. Copulations under laboratory conditions lasted almost two hours. These results are comparable to studies in outdoor cages. Detailed observations on the mating behavior under controlled conditions, and what factors affect mating success, can contribute toward a better understanding of H. grandella to expedite development of control methods.