The shells of edible land snails are very diverse, exhibiting variations in shape, number of body whorls and banding patterns that are useful in the identification of species. This study describes the shell morphometrics and radula structures of two invasive species of the subgenus Lissachatina Bequaert 1950, Achatina fulica Bowdich, 1822, and Achatina reticulata Pfeiffer, 1845 from southwestern Nigeria. Vernier caliper was used to obtain shell measurements, while the radula was examined microscopically. The shells of the two species were dextral, conical with pointed spire. The parietal walls and the columella of the two species were white but columella of A. reticulata had a characteristic thick deposit of white porcelain-like material.  The columella of A. fulica was truncate sharply at the base of the peristome and straight, while the columella of A. reticulata was slantly truncate at the base of the peristome and straight. The shell of Achatina reticulata was larger than that of A. fulica. The radulae of both species were differentiated by the structure of central tooth and the first lateral tooth. The study showed that understanding shell morphology and radula structures could be of importance in the identification and the monitoring of the distribution of invasive species.