Austrapotamobius pallipes is the only native species of crayfish in the Iberian Peninsula. The continuous reduction of density, distribution range and loss of native crayfish populations in the Iberian Peninsula and a growing commercial demand of this product generated the idea of introducing American plague-resistant species for aquacultural trials. Several species of crayfish have been introduced with commercial purposes with a different degree of success in Spain. Up to the present date, out of six species of crayfish that have been object of introduction, only P. clarkii, P. leniusculus, and C. destructor are naturalized. Native populations of A. pallipes were greatly reduced in abundance or become extinct due to habitat alteration, human disturbance, large-scale over-exploitation of natural populations, crayfish plague and the exotic species from North America that are vectors of the Aphanomyces astaci. At present, there are few populations of native crayfish in Spain, and relicts populations in Portugal. P. clarkii accounts for the largest catch. Nearly, all red swamp crayfish is produced in Guadalquivir marshes. Portugal produces a small, but growing volume. Maximum production of red swamp crayfish in Spain was about 5000 tons during 1986, but this production decreased due to inadequate management of the resource and severe drought. The intention of introducing P. leniusculus in Spain was mainly to replace A. pallipes in waters devastated by the plague. The catch of P. leniusculus is at least 600 kg annually and the catch of A. pallipes is less than one ton. However, it must be pointed out that the data on catches available from most regions are estimates. Crayfish production in Iberian Peninsula is growing, especially due to good stocking results with the red swamp crayfish P. clarkii. The signal crayfish P. leniusculus has proved to be an excellent substitute to the indigenous crayfish for recreational purposes. Nevertheless, both species have caused considerable damage to the native crayfish habitats. We briefly review the status of crayfish populations in Spain and Portugal, with special emphasis on P. clarkii, since this species is, by far, the most widespread with wide spread effects. Conservation and management measures for the native and alien species are proposed, with the purpose to make the best of a bad situation.