This cross-sectional study aimed to explore levels of health literacy and factors related to health literacy in choosing medicines and health products among Thai older adults who use smartphones. The study was carried out during March to November 2021 among Senior Schools in the North-eastern of Thailand. The analysing with descriptive statistics Chi-square test and the multiple logistic regression were used to test the association between variables. The results showed that most participants have a low level of health literacy in medication and health products usage. The risking factors that affected to a low-level health literacy were living in a rural area and ability to use a smartphone. Therefore, there should be knowledge enhancement for the older adults with smartphone. Especially, searching information skill and choosing the qualitative media before deciding to buy and use healthy drugs or health products.