Dutch material of the genus Laccobius (Hydrophilidae, Coleoptera) has been examined. A key of the Dutch species and of those of adjacent regions is given. The distribution of the species in the Netherlands is recorded and mapped. Data on the ecology are given. Of all mentioned species the male genitalia are figured. The larva and egg-case of L. minutus (Linnaeus) are shortly diagnosed and figured. It is obvious that L. albipes Kuwert and L. obscuratus Rottenberg are not Dutch species. L. atratus Rottenberg, mentioned incorrectly as a Dutch species in the past, is now recorded for the first time. L. belgicus Gentili, 1979 is a junior synonym of L. striatulus Fabricius.