Аннотация:A new species, Ninastrelnikovia laosica sp. nov., is described on the basis of light and scanning microscope observations. This is the second taxon described in the previously monospecific genus. Ninastrelnikovia laosica sp. nov. differs from N. gibbosa (Hustedt) Lange-Bertalot & Fuhrmann by having a lanceolate valve shape with a second undulation between central part of valve and valve ends. The two species from the genus share the exceptional morphological peculiarity in areola structure not typical of other naviculoid genera. Every stria has a single opening covered internally by a pluriseriate covering that is similar to the weaving pattern on a bast whisp. This structure of pore occlusion is similar between Ninastrelnikovia Lange-Bertalot & Fuhrmann and the genus Navigiolum Lange-Bertalot, Cavacini, Tagliaventi & Alfinito. N. laosica sp. nov. so far is only known from Laos, whereas N. gibbosa has a broader distribution that includes the south-eastern part of North America, Brazil, North Africa, Japan, Laos, Vietnam and Indonesia.