This article presents the results of the first ever assessment of the radon level in the thermal waters of Talysh region. The study of nine natural outlets of the water in seven thermal springs allowed determining the fluctuations in value of radon within very wide range – from 3,73 to 93,3 Bq/l, which is quite characteristic for the ground waters. The springs are classified as the low radon containing waters. Also note is the dependence of radon content from gas composition/ gas saturation of water: relatively low radon content is characteristic for the nitrogen, the highest for carbonate and the medium for the methane waters. The estimated depth of the water bearing horizons does not exceed 2,4 km. For their sanitary-hygienic norms, the thermal waters of Talysh are posing any threat to the health of population whether used for taking baths or drinking, except for the Buludul spring in Yardimly region. The content of radon in the water of this spring exceeds maximum permissible concentration value accepted for potable water more than 1,5 times.