Micropalacontological studies of samples from a supracrustal succession of the Vetlanda Series of South Sweden (> 1740 m.y.); i.e. Svecofennian in age, revealed the presence of a varied assemblage of microfossils. Some of the most representative organic bodies are described, and their origin is briefly discussed. The sedimentary nature of the fine-grained rocks is proved by its microfossil contents.