The type species and nomenclature are discussed in detail of the genus-group names that have been used, correctly or incorrectly, in combination with species recorded from Portugal. This work strictly adheres to the rules of the International Code of Zoological Nomenclature, in order to promote nomenclatural stability. The contents are strictly nomenclatural as no view is taken on the taxonomic validity or rank of the genus-group names. A total of 171 available names are examined. Evidence is provided in each case for the reasons why the stated nominal species is believed to be the validly designated type species. Many instances were found in the modern literature of type species statements not in compliance with the requirements of the Code. In most cases it is a senior synonym that is stated as type species, instead of the nominal species originally included when the genus was established. That, fortunately, does not cause nomenclatural instability but should be corrected. In three cases where nomenclatural stability is threatened, Anisoplia Schönherr, 1817, Phyllopertha Stephens, 1830, and Scarabaeus Linnaeus, 1758, it is suggested that prevailing usage should be maintained until a case is made to the International Commission on Zoological Nomenclature and a ruling is published.