BACKGROUND: Health-related quality of life (HRQoL) is a key variable in the evaluation of health economics. We aimed to evaluate the HRQoL and utility scores of patients with gastric cancer and related precancerous lesions by assessing their quality of life using a single standardized health measurement instrument. METHODS: A cross-sectional study was conducted in six counties in Shangdong Province from November 2019 to March 2020. Subjects with precancerous lesions and gastric cancer (cardia and noncardia) were included and surveyed. Patients were divided into four groups: low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), early gastric cancer (EGC), and advanced gastric cancer (AGC). All patients, except those with LGIN, received treatment. The five-level EQ-5D was used to assess HRQoL and generate utility scores using the Chinese-specific tariff published in 2017. RESULTS: The study included 566 respondents. The average utility was 0.927 for precancerous lesions (LGIN: 0.930; HGIN: 0.926), 0.906 for early gastric cancer (EGC), and 0.756 for advanced gastric cancer (AGC). Visual analogue scale (VAS) means were 76.82 (LGIN: 78.08; HGIN: 74.81), 72.26, and 69.16 for precancerous lesions, EGC, and AGC, respectively. HRQoL was lower in women with AGC than in men (0.612 vs. 0.792, = 0.035). AGC patients were more likely to report problems across all five dimensions than patients in other stages. The proportion of patients reporting pain/discomfort problems was highest across all gastric cancer stages (LGIN, 35.6%; HGIN, 34.4%; EGC, 35.6%; and AGC, 55.7%), followed by anxiety/depression (LGIN, 17.5%; HGIN, 18%; EGC, 22.8%; and AGC, 47.7%). CONCLUSIONS: HRQoL declined as cancer progressed, with the most dramatic decline observed in patients with AGC. A more advanced pathological stage was associated with a greater decrease in health utility. The obtained utilities for different pathological stages of gastric cancer were significant parameters for researchers to perform further cost-utility analysis. Pain/discomfort and anxiety/depression were problems that seriously affected the patients in all groups.