Natural radioactive isotopes occur in various components of the natural environment, including groundwater. The general population, not always aware of possible threats, can use its resources. The activity concentration of some of the radioactive isotopes should be monitored, especially in those intakes from which it is possible to obtain water for human consumption, e.g. in domestic wells. The conducted research was innovative due to the fact that in many countries, including Poland, there are no regulations on waters exploited from home wells using as a drinking water source. As the groundwaters from this area have not been examined for radon (222Rn) and radium (226Ra) occurrence yet, the goal of this research was to perform screening tests in this part of the Fore-Sudetic Monocline. For this purpose, the authors have measured the concentration of222Rn and226Ra activity in groundwater collected from this geological unit located in south-western Poland.222Rn and226Ra occurrence was researched, and specific electrolytic conductivity, redox potential, pH and temperature were measured in 52 groundwater samples.222Rn activity concentration ranged from 0.18 to 19.78 Bq/dm3. Only in three cases,226Ra activity concentration reached a value above the lower detection limit of the applied method, i.e. 0.05 Bq/dm3(max. 0.77 Bq/dm3). The authors present completely new data on the occurrence of these radioactive isotopes in the waters of the first aquifer in the Fore-Sudetic Monocline, which is not without significance for the health of consumers of these waters.