Eunotia triodon has longer, wider valves.
Eunotia tridentula has less cuneate undulations on the dorsal margin and the middle undulation is more pronounced than others, mainly in the smallest specimens. Eunotia tridentula also has lower stria density.
Eunotia nupeliana has wider valves and the central undulation is less pronounced than the others.
Eunotia perpusilla has two subapical swellings on the ventral margin.