Marine sediments are characterized by intense degradation of sedimenting organic matter in the water column and near surface sediments, combined with characteristically low temperatures and elevated pressures. Fungi are less represented in the microbial communities of sediments than bacteria and archaea and their relationships are competitive. This results in wide variety of secondary metabolites produced by marine sediment-derived fungi both for environmental adaptation and for interspecies interactions. Earlier marine fungal metabolites were investigated mainly for their antibacterial and antifungal activities, but now also as anticancer and cytoprotective drug candidates. This review aims to describe low-molecular-weight secondary metabolites of marine sediment-derived fungi in the context of their biological activity and covers research articles published between January 2016 and November 2020