The primary structure of 26S ribosomal RNA from mitochondria of the dicotyledoneous plant Oenothera berteriana is inferred from the sequence of a cloned rDNA restriction fragment. A tentative secondary structure model valid for Oenothera and for the major part of maize mitochondrial 26S rRNA has been constructed in analogy to the refined german model for E. coli L-rRNA (Maly and Brimacombe 1983). The derived structure generally matches the eubacterial model providing further support to the E. coli consensus structure. Some structural features however show eukaryotic characteristics. Possible interactions between L-rRNA, 5S rRNA and initiator-tRNA are discussed.