The giant African snail Lissachatina fulica (Bowdich, 1822) is a protandrous hermaphrodite gastropod; that is, it develops the male reproductive system first and then the female reproductive system. An individual can lay more than 400 eggs in the same posture, which contributes to its invasive potential. Due to the difficulty in differentiating hermaphrodite individuals, in this study, we evaluated whether the length and shape of the shell contribute to recognizing individuals with female reproductive structures. For this, we classified 104 individuals collected in Brasília (Brazil) according to the presence or absence of an albumin gland and uterus and evaluated the shell length and two indices that reflect its shape in each group. The shell length and two shape indices overlapped between groups. However, the length and one of the indices (how many times the distance between the first suture and the shell aperture fits into the shell width) correctly classified at least 88% of hermaphrodite individuals when applied individually. When these two indicators are adopted simultaneously, the percentage of success in identifying hermaphrodites is greater than 98%. In hermaphroditic individuals, the shell length is generally greater than 5 cm, and the shape index described above is generally less than or equal to 2.1. Our proposal facilitates the recognition of potentially hermaphroditic individuals in the field, thus contributing to the management of this important invasive species.