During the period of 2011–2018, more than 14,000 batches of Japanese foodstuffs that were imported into Taiwan were inspected. Among these, only trace levels of radiation were detected in 224 batches. Nevertheless, there is growing concern in Taiwan about the threat posed by radionuclide contamination to food safety. To assess this risk, we conducted a detailed investigation of this issue entailing an estimation of the internal radiation dose and lifetime cancer risk associated with food ingestion among Taiwan’s population. Our results indicated that in the worst-case scenario, the highest exposure level of the annual committed effective dose (CED) from ingestion of cesium radionuclides within males aged 15–19 years was 0.0057 mSv per year. This value was well below the CED of 1 mSv per year for radionuclides. Moreover, in 19–65 years male consumer only-max group, the nominal risks for solid cancers, leukemia, and thyroid cancer were 5.32, 1.36, and 0.23 per 10,000 cases, respectively, calculated on the basis of conservative assumptions (worst-case scenario). In 19–65 years female whole group-mean group, the nominal risks for solid cancers, leukemia, thyroid, and breast cancer were 0.14, 0.04, 0.03, and 0.19 per 10,000 cases, respectively. In the general situation, we posit that in the current regulatory policy and radioactivity exposure scenario, radionuclides present in food pose no significant safety risk in Taiwan.