This study of the Portuguese Magelonidae aims to increase our knowledge of European Magelona species. Magelona specimens were collected from the southwestern Portuguese continental shelf during the SEPLAT 6 & 7 cruises, between April 1981 and October 1983. Six species of Magelona were found: M. alleni, M. filiformis, M. johnstoni, M. minuta, M. wilsoni and a further species, M. lusitanica sp. nov., which is described herein. Magelona lusitanica sp. nov. shares many similarities with M. cornuta from the Gulf of Oman. Examination of M. wilsoni specimens collected highlighted the need for a re-description based on type material. This re-assessment reveals several features not mentioned in the original description, in particular the crenulate anterior prostomial margin and the shape of thoracic lamellae. Due to the condition of the paratype material (holotype believed lost), specimens of M. wilsoni from Portugal and further specimens from the Gulf of Lions are examined and described. Previous records of Magelona from Portuguese coasts are reviewed and commented on. A key for European species of Magelonidae is given.