According to F.J. OCHARAN (1987, Los odonatos de Asturias y de Espaha: aspectos sistemalicos y faunisticos. Tesis doctoral, Univ. Oviedo) and C. BONET-BETORET (1990, Contribution al esludio de los odonalos adultos de la provincia de Valencia, Tesis doctoral, Univ. Valencia), the last record of O. costae from Spain was that of J.M. ANDREU RUBIO (1953, Publnes Univ. Murcia 15: 5-15, figs 1-11 excl.), from Caravaca in the Murcia province. Other recent listings of this species were only compilations of older data from the Zaragoza. Huesca, Alicante, Tarragona. Jacn, Murcia and Madrid provinces. All these were listed by OCHARAN (1987, op.cit.). In view of the lack of recent records of this Ibero-Maghrebian species, its current occurrence in the Iberian Peninsula may be questioned. We were very interested, therefore, to rediscover this small gomphid in two localities in northeastern Spain (Aragon province) during 1991. The first observation was done on June 30, along a right-hand tributary of the Rio Ebro, 4- -6 m wide with a low current, many meanders and scarse scrubby vegetation. Three males were seen during half an hour but the end of the day prevented any more complete inventory of the local population. The species could not be retrieved at this very place during 1992 and its local status remains uncertain. Other Odonata were Calopteryx haemorrhoidalis (Vander L.)> C. Xanthostoma (Charp.), Platycnemis latipes Ramb., Coenagrion mercuriale (Charp.), Cercion lindenii (Sel.), Ischnura graellsii (Ramb.), Ceriagrion tenellum (de Vill.), Onychogomphus forcipatus unguiculatus (Vander L.), Sympetrum striolatum (Charp.) and Crocothemis erythraea (Brulle).