SummaryWe have identified substitutions in the 31 untranslated region of the bovine myoglobin gene, one of which affects an MboII restriction enzyme site resulting in a bi‐allelic restriction fragment length polymorphism. Co‐dominant inheritance of the alleles in three reference families was observed using a polymerase chain reaction—restriction fragment length polymorphism assay. The distribution of the alleles seems characteristic of cattle type—one of the alleles was not detected in purely taurine breeds. Furthermore, we mapped, using the polymerase chain reaction on a bovine–rodent somatic cell hybrid panel, the myoglobin gene to bovine chromosome five. It is therefore syntenic with γ‐interferon and insulin‐like growth factor in which we have not found polymorphism. The myoglobin locus therefore serves as a type one marker on bovine chromosome five.