ERα36 is a recently cloned variant of estrogen receptor-alpha which has been proved to play an active role in a series of malignant diseases.ERα36 expression was examined using immunohistochemical methods with sections from 126 resected NSCLC specimens. The immunoreactivity of ERα66 was also studied as a comparison. Kaplan-Meier method and multivariable Cox proportional hazards regression analyses were used to examine the relationship between ERα36 and survival.ERα36 was more highly expressed in NSCLC patients compared to ERα66. ERα36 expression has a strong correlation with histology (AC: 53/70, SCC: 16/56, P<0.000) and had a significantly positive correlation with lymphatic metastasis (P=0.014) in adenocarcinoma. High ERα36 expression was correlated with poorer overall survival (OS) (P=0.020) and disease-free survival (DFS) (P=0.024) in adenocarcinoma. Furthermore, ERα36 status was a significant independent prognostic factor of OS (P=0.018, HR: 3.142, 95% CI: 1.215-8.128) and DFS (P=0.024, HR: 2.720, 95% CI: 1.141-6.486) in lung adenocarcinoma patients.ERα36 had a high expression mainly in adenocarcinoma and the high expression of ERα36 was strongly correlated with more advanced regional lymph node metastasis and poor survival in lung adenocarcinoma.