Current nutritional guidelines for stomach cancer survivors (SCS) mainly focus on the influence of surgical resection of the stomach, with limited guidance regarding a wider range of food options. We aimed to investigate the factors associated with healthier dietary changes in Korean adult SCS. This cross-sectional study assessed dietary pattern change after cancer treatment for 11 food categories, using a self-administered questionnaire. A ‘healthier dietary change’ was operationally defined as reduced consumption of red and processed meat, grains, salt, and burnt food, and increased consumption of poultry, fish, vegetables, fruits, legumes, and dairy products. Among a total of 624 SCS, approximately 60% of participants reported healthier directional dietary changes in three or more food categories, while 9.1% reported no changes. There was no significant difference in dietary habit changes between surgery types. Multivariable adjusted analysis showed that elderly and long-term survivors were inversely associated with a healthier dietary change. SCS with higher educational achievement and income were more likely to make healthier changes in their intake of processed meat, vegetables, fruits, burnt food, or salt. SCS with higher levels of fear of cancer recurrence, anxiety, or depression were more likely to follow healthier dietary changes for fish, meat, fruits, grains, or burnt food. Change in dietary pattern varied across different food items and was associated with various characteristics of SCS. It is crucial to repeatedly provide SCS with information about healthier dietary patterns, considering their sociodemographic, clinical, and psychological characteristics.