Groundwater, once surfaced, may contain some radioactive elements that can increase thenatural radioactivity levels of different environmental factors, having a varied impact on the ionizingradiation dose received by the human body. This paper presents radium in groundwater concentrationmeasurements from various galleries of disused mines. The studied area is located in Gutâi, Rodna andMaramures Mountains, in the northern region of Transylvania, Romania. In order to determine the radiumconcentration in the collected water samples, two methods were used, both based on radium and its decayproduct, radon, secular equilibrium. After achieving the radioactive balance, the radon was measuredusing two types of scintillation Lucas cells. The obtained values of radium concentration range from 20 to510 mBq/l for the 1 liter Lucas cell method and from 50 to 501mBq/l for the 145 ml Lucas cell method.The highest radium concentration values were found for samples from Nistru Gallery (510mBq/1,respectively, 501mBq/l) and Herja Gallery - Baia Mare (410 mBq/l, respectively, 463 mBq/ l). The lowestvalues radium was determined for samples from Boului Gallery - Baia Sprie (20 mBq/l and 50 mBq/l)and Băiuţ Gallery (45 mBq/l, respectively, 50 mBq/l). The average obtained radium concentrations valuesare of 138 mBq/l for 1l Lucas cell method and 171 mBq/l for 145 ml Lucas cell method.