The banded murex Hexaplex trunculus was sampled at Menzel Jemil and Bizerta Channel (Bizerta Lagoon, northern Tunisia) to study imposex, growth, and reproduction. Butyltin concentrations were analyzed in females from the 2 sampling sites using the gas chromatographic flame photometric detection technique. Results showed that the Bizerta Channel population was severely affected by imposex, which was confirmed by the high level of butyltins recorded in females from this site. Growth in shell width and shell weight was higher in Bizerta Channel, whereas growth in shell aperture and flesh weight was favored in Menzel Jemil. The assessment of reproductive activity, made by calculating fecundity and using 2 condition indices, showed that the Menzel Jemil population was reproductively more active.