Despite the increasing number of reports on the deep-sea molluscs from the south-western Atlantic, we know very little about the protobranchs. The lack of information on the protobranch Pelecypoda off southern Brazil is reflected in the genus Yoldiella. This contribution is part of an effort to increase the knowledge about this group off the Brazilian coast. Eight species of Yoldiella are recognized here. For Yoldiella biguttata, previously reported from Brazil, the known distribution is extended southwards to the Campos Basin. For Yoldiella similis this is the first record in the western Atlantic Ocean. For Yoldiella extensa and Yoldiella aff. jeffreysi this is the first record for Brazil. Four previously unknown species are described, Yoldiella lapernoi sp. nov., Yoldiella paranapuaensis sp. nov., Yoldiella arariboia sp. nov. and Yoldiella curupira sp. nov. Considering only conchological features for the Atlantic species we could propose some clusters of species of Yoldiella.
