Boujad is a Moroccan city located in the region of Beni Mellal - Khenifra, and is considered until now as a spiritual center welcoming travelers from the Kingdom in search of religious precepts. Investigations carried out in the ancient medina of this city reveal the presence of underground cavities of natural and anthropic origin, which repeatedly cause collapses and considerable human and material damage. In order to characterize the subterranean network of this city, a geophysical study was carried out by means of electrical prospecting of the subsoil, complemented by a seismic refraction investigation, in order to investigate the geological and geophysical characteristics of the underground cavities, and then to produce a detailed mapping of the anomalies detected within the ancient medina of Boujad. The geophysical investigations thus revealed a heterogeneous subsoil dominated by limestone formations and sheltering several underground anomalies, and allowed, by superimposing the maps of anomalies drawn up at the end of each technical investigation, then correlating and verifying the results collected in relation to the data from the surveys and preliminary investigations, to draw up a synthetic map of the main areas concerned by the presence of cavities which are quite varied and spread over the entire extent of the ancient medina of Boujad.