The aim of this work was to check and determine the activity concentration of 40K,226Ra and 228Ra in some commercial bottled water used as drinking water in Cameroon by means of using high-purity germanium based gamma spectrometry techniques.The water samples were firstly chemically treated by adding nitric acid and then pre-concentrated further by evaporating them up to a certain level.The water residues were transferred to small cylindrical containers and were kept sealed in order to ensure secular equilibrium between U-238,Th-232 and their daughter products.The calculated activity concentration for 226Ra (U-series) and 228Ra (Th-series) were used to estimate the annual effective doses for different age groups<1y,1-2y and ≥17y by taking into account the ingested dose conversion factors obtained from the International Commission on Radiological Protection (ICRP) as well as their yearly average bottled water consumption.The paper presents the overview of the technique used and the summary of findings from this survey.