Usually, these animals inhabit caves or groundwater. They occur mainly in western Eurasia, in regions that were not covered by the Pleistocene ice sheets. Some are found southwestwards of this range; on the other hand this genus is largely missing from Iberia. In their main range – the central Mediterranean region through Central and Eastern Europe to the Ukraine – they are among the most significant organisms inhabiting the groundwater.
The genus Niphargus contains the following species: