In the framework of a European Geothermal Project, three boreholes were drilled at Soultz-sous-Forets. Rhinegraben, which reached the hot and fractured granitic basement. Fresh water will be injected into one borehole, and recovered hot from the other, To design this reservoir, a knowledge of both the paleo-fracture pattern in the granite and the orientation of the present-day stress field is required. Fracture analysis was carried out on borehole images coming from different boreholes. Two types of logging tools were used to produce these images :acoustic tools (BHN, UBI) and electric tools (FMI, FMS). Fractures observed have two origins : pre-existing ting fractures and induced fractures. Pre-existing fractures showed a symmetrical pattern with a principally N-S direction. These fractures have been created during the tectonic history of the massif since the Visean. This fracture pattern appears to be related to the graben opening which took place during the E-W extensional Oligocene regime. The strike-slip fractures created from the other tectonic regimes (strike-slip compressive stress state) seem under-sampled by the borehole, However, another fracture set (N50 degrees E) exists but is visible on the acoustic image only. The N-S fracture set is in the present-day horizontal stress direction and locally contains natural fluid. Electric tools are very sensitive to the occurrence of fluid. Fractures with offset are easily detected by acoustic tools. The analysis of induced fractures indicates directly the present-day stress field. Their direction is parallel to the direction of the maximum stress in the plane perpendicular to the borehole axis, This direction is N125 degrees E in the EPS1 well and N160 degrees E in the upper part of the GPK1 well, located 500 m apart, but N180 degrees E in the lower part of the GPK1 well and N170 degrees E in GPK2 well. These variations of the direction of induced fractures are due to a variation of the present-day stress field at the site scale and at the borehole scale. The results of other in situ present-day stress measurements confirm this variation of the stress field. This stress perturbation could be due to the occurrence of major faults in the rock volume. The boreholes have intersected a fault zone, which may be the cause of stress deviation.