The present study was conducted to determine the diversity and density of the aquatic Gastropoda community, and study some factors associated with water quality in Shatt al-Arab River; namely, water temperature, salinity, pH, and dissolved oxygen. Samples of aquatic Gastropoda and water were collected monthly from three study sites along with Shatt Al- Arab River in Basrah Province,  during the period from January to December 2019. The highest species diversity of Aquatic Gastropod snails were found in Al-Qurna site (site 1) (10 species), while in Al-Garmat Ali site (site 2) (9 species) and in Abu Al-Khasib site (site 3), 5 species were found. A total of 12239 individuals of the three sites were collected during the study period. The higher annual density was recorded in aquatic Gastropoda snails B. bengalensis (Lamarck, 1822) with 5333, 1800 and 875 Individual/m² in the three sites, respectively while the other aquatic Gastropoda species together recorded a density of 1691, 1313 and 1227 Ind./m² in the three sites, respectively. The monthly densities of Bellamya bengalensis varied from 0 Ind./m² in January, October, November and December 2016 at Abu al-Khasib site to 966.0 Ind./m² in June 2016 at Al-Qurna site. Statistical analysis showed significant differences in dissolved oxygen and salinity between the first and the third sites. The temperature correlated positively with the mean of pH and salinity, and negatively with the number of the recorded species and the total densities of the aquatic Gastropoda species. In addition, salinity correlated positively with the mean density of Gastropods. On the other hand, the total number of the recorded species correlated positively with the total densities of aquatic Gastropoda species.