Long noncoding RNA LINC00504 (LINC00504) has been demonstrated to be dysregulated in several tumors. However, its function in tumor progression remains largely unclear. The goal of our present study was to determine the expressions of LINC00504 in non-small cell lung cancer (NSCLC) and its clinical associations. The expressions of LINC00504 were detected in 181 pairs of NSCLC specimens and adjacent normal tissues using qRT-PCR assays. Chi-square tests were applied to analyze the associations of LINC00504 expressions with various clinicopathological parameters of NSCLC specimens. The possible associations between LINC00504 expressions and overall survival were investigated using Kaplan-Meier assays. Univariate and multivariate assays were performed to further determine the prognostic value of LINC00504 levels in NSCLC patients. We showed that LINC00504 expressions were distinctly decreased in clinical NSCLC specimens compared to adjacent non-tumor specimens (p < 0.01). High LINC00504 expressions were strongly associated with TNM stage (p = 0.038) and lymph node status (p = 0.010). In addition, Kaplan-Meier analysis indicated that NSCLC patients with high LINC00504 expression tend to have shorter overall survival (p = 0.0036). More importantly, the results of multivariate analysis indicated LINC00504 as an independent prognostic marker (p = 0.0028). These findings revealed that LINC00504 might act as a prognostic biomarker for NSCLC patients.