Objective To investigate the values of mRNA and protein of excision repair cross-complementation group 1 (ERCC1) in predicting the prognosis of advanced gastric cancer patients treated with FOLFOX4 regime in high-altitude areas. Methods Seventy patients with advanced gastric cancer were enrolled in this study, 60 patients were eligible for analysis. All patients received FOLFOX4 regime repeated every two cycles. RT-PCR was used for analysis of ERCC1 mRNA; immunohistochemistry was used for analysis of ERCC1 protein expression. The relationships of mRNA and protein of ERCC1 with objective response rate (ORR) and progression-free survival (PFS) time were analyzed. Results ERCC1 mRNA expression was negatively associated with objective response rate (P = 0.038) and progression-free survival (P = 0.032). ERCC1 protein expression was not correlated with ORR of FOLFOX4 treatment (P = 0.089), but was negatively correlated with PFS (P = 0.039). Conclusions In high-altitude areas, the expression of ERCC1 mRNA in advanced gastric cancer patients is negatively correlated with PFS and ORR of FOLFOX4 treatment; the expression of ERCC1 protein is not associated with ORR, but has correlation with PFS in advanced gastric cancer patients.