The European species Nigrobaetis gracilis (Bogoescu & Tabacaru 1957) and more than 19 Asian and African species of Nigrobaetis Kazlauskas (in Novikova & Kluge) 1987 belong to the subgenus Margobaetis Kang & Yang 1994, which is characterized by peculiar asymmetric eggs and narrow paraglossa of larval labium. A new synonymy is established: Nigrobaetis (Margobaetis) minutus (Mller-Liebenau 1984) = N. paramakalyani Kubendran & Balasubramanian in Kubendran et al. 2015 = N. sumbensis Kaltenbach & Gattolliat 2023, synn.n.; winged stages (male and female imagines and subimagines) and eggs of this species are described for the first time. N. (M.) minutus is widely distributed on Oriental Region, being revealed in West Malaysia, Southern India, Sumba and Sulawesi islands in Indonesia. Winged stages (male and female imagines and subimagines) and eggs of Nigrobaetis (Margobaetis) klugei Sivaruban et al. 2022 are described for the first time.