This is a phylogenetic and systematic treatment of all oedemerid larvae known either from accounts in the literature or from existing specimens. The larvae are divisible into three groups: 1) the Calopodinae; 2) the Nacerdinae, Ditylini, and Asclerini; and 3) the Oedemerini. The Calopodinae gave rise to the Nacerdinae-Ditylini-Asclerini group, and the Oedemerini appear as specialized derivatives of the Asclerini. Keys and descriptions accompanied by illustrations are provided for all taxa. Most oedemerid larvae inhabit moist, rotting wood. The Oedemerini, however, usually have been taken from the stems and roots of plants. With the exception of Nacerdes melanura, the wharf borer, no oedermerid is presently considered of economic importance. However, in view of the incomplete knowledge of their biologies, others cannot be disregarded as potential pests.