A brief account of the sightings of Cacyreus marshalli in the Spanish Pyrenees. This is a new species in Europe, originating from South Africa and having first been reported in Majorca in 1989. The foodplant of this member of the Blues is the geranium. In some parts of southern Europe C. marshalli does in fact pose a threat to geranium nurseries. It seems unlikely the butterfly will move further to northern Europe as the species is unable to survive the winter frost.