The north-western regions of the Indo-Pakistani subcontinent have been the craddle of one of the most famous civilizations of the Ancient world. But until the last quarter of the XXe century, the antecedents of the Indus civilisation with its major cities such as Mohenjo-daro or Harappa were poorly known. It was commonly thought that small farming communities coming from the Iranian Plateau began to settle down in Balochistan in the first half of the 4th millennium BC. Other groups with cultural links with southern Central Asia would also have reached the border of the Indus valley around 4000BC. The discovery in 1977 of an aceramic Neolithic settlement in the northern area of the site of Mehrgarh has opened a new chapter in the archaeological studies in this part of the world. It became then obvious that the archaeological sequence of the Greater Indus regions, since the 8th millennium BC till the emergence of the Indus civilization, c. 2500 BC, was far more impressive than it was thought before. Alongside the excavations conducted in the Chalcolithic/Bronze Age occupation deposits of Mehrgarh, from 1976 until 1985, the Neolithic settlements provided a first set of information about periods so far unknown in these regions. Some of the information from the 1977-1985 excavations were regularly published in the field reports (C. Jarrige et al. 1995). In 1996, it was decided to resume work in the Neolithic area of Mehrgarh within a program of four seasons of fieldwork. Since all the efforts of the archaeological team were only concentrated on the aceramic Neolithic settlement, these four seasons of fieldwork allowed a much larger exposure of the successive occupation levels and graveyards from the natural soil up to the surface. This work gave the opportunity to fix in a much precise way than before the whole archaeologial sequence of the aceramic Neolithic settlement. The first ever published overview of the Neolithic period at the western border of the Indus valley has been added to the four reports.