DENIS is a project to survey the all-southern sky in three wavelength bands (Gunn-i 0.82 μm; J, 1.25 μm; and K_s, 2.15 μm) with limiting magnitudes 18.5, 16.5 and 14.0, respectively. The observations are performed with the 1m-ESO telescope at La Silla (Chile). The DENIS instrument is made up of a 3-channel camera built of commercially available detector arrays by the Observatoire de Paris and with major contributions from other European Institutes, notably: the IAS in Frascati, the Observatoire de Grenoble, the University of Innsbruck, the Observatoire de Lyon, and the IAC in Tenerife. The survey is carried out by observing strips of 30 ° in declination and 12 arcminutes in Right Ascension with an overlap of 2 arcminutes between consecutive strips. The survey started at the end of 1995 and is expected to be completed in 2000. The data are reduced in two consecutive steps, the first at the Institut d'Astrophysique de Paris and the second at the Leiden Observatory. The position of a general extracted point source is provided with an accuracy better than 1 arcsec and its magnitude to better than 0.1 mag. The data will be made publicly available as soon as possible after completing the data reduction. The Centre de Donnees Astronomiques de Strasbourg (CDS) is implementing the final databases and is providing access of the processed and calibrated data to the worldwide community. The principal investigator of the DENIS project is N. Epchtein (Observatoire de la Cote d'Azur); scientists and engineers from seven European countries and from Brazil are involved. (1 data file).