An archaeological survey was carried out by a French team in November and December 2002 in the Somaliland Republic. The objective was the search for rock shelters and caves containing stratified archaeological infills capable of documenting the period when production economy appeared in this part of the Horn of Africa (circa 5th and 2nd millenia B.C.). The Las Geel site, a granite rock sheltering about ten shelters decorated with polychrome paintings, was discovered in the course of the survey. These paintings, in an excellent state of preservation, mainly represent humpless cows with large lyre-shaped or arched horns and the neck decorated with a kind of plastron. The cows are accompanied by stocky human figures with spindel-shape legs and raised arms. There are also some figures of canidae placed beside men, a single giraffe and some antelopes. The evident superposition of several graphic styles will no doubt make it possible to establish a chronology of Neolithic or Protohistoric rock art in this part of the Horn of Africa. Through the abundance of its paintings, their quality, the originality of the type of representation of bovines and human figures, the Las Geel site will henceforth take its place among the major Holocene sites of rock art in this region of Africa. A future mission planned for November 2003 will make it possible to undertake a detailed study of these paintings and their archaeological context. This note constitutes a preliminary presentation of this exceptional discovery.