Owing to the community engagement of the gastropod collection in the south western ecosystems in Bangladesh, the gastropod molluscs are getting important attention in terms of edible and non-edible purposes while detailed morphological information about the gastropods is scarce in this area. The present research has investigated the morphological variability of the gastropod molluscs (Pila globosa) in the six localities of south-western coastal Bangladesh (such as, Khulna, Bagerhat, Satkhira, Gopalganj, Pirojpur and Jessore). A total of 2160 gastropod samples (Pila globosa) were collected from July to December monthly over the two consecutive years of 2013 and 2014. The results of the analyses revealed that the maximum monthly mean values of the dry shell mass and the dry body mass were found in November, indicating the complete growth and development of the gastropods in the coastal environment. One-way ANOVA and ANCOVA show that there is a significant morphological variability of Pila globosa among different localities in the south-west coastal Bangladesh, while the covariate of water salinity significantly affects the aperture length of it; the covariate of electrical conductivity of soil significantly affects both the height and aperture length; the covariate of sodium contents of the soil significantly affects the aperture length of the gastropod mollusc. The results also revealed that the morphological variability of the mollusc P. globosa is linked to complex ecological systems and habitat variation.