This file contains data on numerical abundance of early stages of fishes (mostly larvae) in winter (December 2009) and summer (July 2010) in the Balearic Islands region. A relatively small area was repeatedly sampled throughout the day. Samples were obtained by means of a 0.25 m2 MultiNet HYDRO-BIOS (Weikert and John, 1981) in winter, and a Multiple Opening/Closing Net and Environmental Sensing System (Wiebe et al., 1985), MOCNESS-1 m2, in summer. Hauls were performed both day and night, discriminating different layers and mainly in the epipelagic zone. Samples were fixed on board and stored in a 5% buffered formalin and seawater for later sorting and identification in the laboratory. These data were obtained within the project: "Estructura y dinámica del ecosistema bentopelágico de talud en dos zonas oligotróficas del Mediterráneo: una aproximación multidisciplinar y a distintas escalas temporales en las Islas Baleares", financed by the Spanish Ministerio de Ciencia e Innovación CTM2007-65844-C03.