In the present study, digital imaging was used to measure length-frequency data from all major migratory habitats of Hilsa. This investigation appears to be the first to generate information using this technique regarding population dynamics and stock status of Hilsa, and subsequently, a guideline for using this method was developed. This is also the first time that the spatial and temporal size composition of Hilsa in sanctuary, nonsanctuary, and marine habitats were also compared. Based on the findings and lessons learned after reviewing the present management activities, suitable short- and long-term management options are suggested for the sustainable management of the Hilsa fishery in Bangladesh.