We review the distribution of the water scavenger beetles (Hydrophilidae) in the northern part of Tunisia, based on data from 54 sites collected over the course of a year. In total, 21 hydrophilid species were found. The most interesting ones from the zoogeographical point of view are: Enochrus nigritus Sharp, 1872, Enochrus affinis Thunberg, 1794, Laccobius revelierei Perris, 1864 (all newly recorded for Tunisia), and Laccobius orientalis Knisch, 1924 and Berosus spinosus Steven, 1808 (newly recorded for northern Africa). An updated checklist of hydrophilid species occurring in the northern Tunisia is provided. The composition of the hydrophilid fauna in the area is assessed using the indexes of richness, abundance and diversity. We discuss possible causes of this phenomenon; identify the most valuable water beetle habitats within the investigated area that should be protected by law.