<p>Activity concentrations of ²³⁴U and ²³⁸U as well as ²³⁴U/²³⁸U ratios were investigated in the muscle and digestive diverticulum organs of ten size group samples of Asian green mussel (<i>Perna viridis</i>) from Binh Thuan, Vietnam by alpha-spectrometry, and radiological risk assessment was carried out. The ²³⁴U and ²³⁸U activities in muscle tissues and digestive diverticulum ranged from 1.4 ± 0.1 to 53.2 ± 4.3&#xa0;Bq.kg⁻¹, from 1.2 ± 0.2 to 57.2 ± 4.5&#xa0;Bq.kg⁻¹, and from 3.8 ± 0.3 to 45.0 ± 7.5&#xa0;Bq.kg⁻¹, from 3.1 ± 0.2 to 42.0 ± 6.6&#xa0;Bq.kg⁻¹, respectively. Uranium activities showed a decreasing trend in groups with smaller shell lengths from 5 to 6.5&#xa0;cm and stabilized in individuals larger than 7&#xa0;cm. Bioaccumulation factors were higher in smaller mussels, demonstrating greater accumulation, indicating their suitability as sentinel organisms for further study and radioecological monitoring of uranium isotopes. The ²³⁴U/²³⁸U activity ratios in digestive diverticula were consistently higher than in muscle tissues, suggesting dual uranium uptake pathways: direct absorption from seawater and ingestion of contaminated foods. The average risk to the mussels from exposure to uranium alone is below the ERICA screening reference level of 10&#xa0;µGy.h⁻¹, but a single sample exceeded this level indicating further investigation is necessary. Annual committed effective doses from consuming mussels containing ²³⁴U and ²³⁸U ranged from 2.11 to 43.60&#xa0;µSv.y⁻¹, with a mean of 12.04&#xa0;µSv.y⁻¹. While doses from ²³⁴ and ²³⁸U are within UNSCEAR safety thresholds, other radionuclides (e.g., Po, Pb, and Ra isotopes) should be considered for a comprehensive assessment. Not consuming small mussels is recommended due to higher potential radionuclide accumulation.</p>