Clean drinking water supply is a major concern to the population of the urban municipality of Boké, Republic of Guinea. This study is aimed to investigate the favourable geological structure for the accumulation of groundwater in Boké. Apparent resistivity data was collected by using the Schlumberger-type vertical electrical sounding technique. The apparent resistivity values were obtained on a bi-logarithmic scale in which the distances AB/2 were plotted on the abscissa and the resistivities are on the ordinate. It found the number of terrains and their characteristics (resistivity and thickness) in the area and the behaviour of the current in the soil through a curve. The results show that the structures favourable to the accumulation of groundwater were fractured dolerites, cracked shales and cracked or crushed sandstones. The sandstones were the most important in terms of the amount of water. They are located at a depth of more than 100 metres. It was also found that dolerites and shales are located at shallower depths (less than 100 m).