We evaluated the usefulness of a genetic linkage between the U1 and U2 small nuclear RNAs for species identification. Six soles belonging to the genera Solea, Dicologlossa, and Microchirus were studied. A simple methodology based on two single PCRs is described. Reproducible band profiles were generated for all samples. This rapid and discriminatory molecular method is highly promising for determining the authenticity of sole fillets in the food industry.