Acoustic techniques have been used for the first time to evaluate the abundance and distribution of the Aphia minuta stock (Pisces: Gobiidae) from the Island of Mallorca (Baleares, Spain). Acoustic surveys have been carried out during three consecutive seasons (1993, 1994 and 1995) in the more important fishing zone of this island, the Bay of Alcudia. Indices were obtained for abundance (m3) of this goby at the beginning of the fishing season. The volume of A. minuta has decreased from 12,902,751 m³ in January 1993 to 1,161,248 m³ in January 1995. The catches obtained have gone from almost six tonnes in 1993 to be practically nil in 1995.