Shallow to deep water (recorded to 3.7 m) of lakes, ponds, rivers, and streams; sometimes rooted in organic mud of bog lakes.

Some vegetative specimens cannot be reliably distinguished from Potamogeton pusillus, but fortunately, P. foliosus fruits reliably. Potamogeton pusillus can supposedly be identified vegetatively by the presence of glands on the stem at the base of the leaves, but in our specimens (including good fruiting ones), such glands are usually absent, weak, or obscure.