Although Spaniards of a certain age would probably not confuse these terms, I have seen the former called by the latter’s name several times both in translation and on the Web, so it is perhaps worth underscoring the difference. Cortes Generales is the name of Spain’s bicameral parliament including, as its lower house, the Congreso de los Diputados (“House of Deputies”) and upper house, the Senado (“Senate”). Las Cortes Generales were established and are regulated in Title Three of the Spanish Constitution of 1978, and its members are known respectively as diputados and senadores.
In contrast, Cortes Españolas was the unicameral legislative assembly under the Franco regime, established in 1942 and existing until 1977. Its members were known as Procuradores en Cortes and should not be confused with procuradores de los tribunales, who represent the interests of their respective parties before the Spanish Courts.