ABSTRACT. – Accurate information on density, structure and vulnerability of wild populations occupies a central place in conservation biology. A mark-recapture study was carried out during the 2003 activity season in a population of Testudo graeca in the Central Jbilets (Morocco). Juveniles were poorly represented in our data set, suggesting that juvenile numbers are actually low in our population and/or that tortoises are easier to capture after the behavioural shift of the acquisition of sexual maturity. Although the studied population was localised in a severely overgrazed area, the estimated adult and sub-adult population density, six individuals/ha, was relatively high comparatively to available estimates in other places. However, within three months of fieldwork, it was possible to capture most of the adults (60%), suggesting that Testudo graeca graeca populations are very sensitive to illegal and repeated harvesting. Long-term monitoring of the population is required to better appreciate the demographic trend of this population.