<p>Radon (²²²Rn) has emerged as one of the most serious radionuclides of health concern due to its internal radiation dose to organs and radiotoxic effects. The concentration of ²²²Rn and radiological dose in branded sachet water produced and consumed in Asaba, Nigeria is investigated in this study. Twenty four samples of sachet water of different brands were analyzed for ²²²Rn using RAD7 detector in triplicate. The result showed ²²²Rn concentration in the range of 0.276 ± 0.028 to 4.159 ± 1.391&#xa0;Bq&#xa0;l^–1 with a mean concentration of 0.859 ± 0.76&#xa0;Bq&#xa0;l^–1. The values are lower than recommended safe limits of 100.0 and 11.1&#xa0;Bq&#xa0;l^–1 advised by the World Health Organization and the United States Environmental Protection Agency, respectively. The ingestion annual effective dose was estimated as 15.99 μSv y^–1 (for infants), 7.83 μSv y^–1 (for children), and 8.43 μSv y^–1 (for adults). These dose values are lower than the WHO radon dose criteria level for drinking water. This implies that branded sachet water in Asaba is within radon safe limit with no significant health consequences to consumers. The data will help in policy development of safe drinking water resources as well as a reference material for future studies on natural radioactivity monitoring of different water sources in the region.</p>