In our previous study, we had identified SOX30 as a novel tumor suppressor that acts through direct regulation of p53 transcription in human lung cancer. Here, we sought to determine the clinical relevance of SOX30 expression in a series of surgically-resected non-small cell lung cancer (NSCLC) patients. Analysis of SOX30 expression and clinico-pathologic features reveal a significant correlation of SOX30 expression with histological type (n = 220, P = 0.008) and clinical stage (n = 220, P = 0.024). Kaplan-Meier analysis indicates an association of high SOX30 expression with better prognosis in NSCLC patients (n = 220, P = 0.007). Via multivariate Cox-regression analysis, SOX30 expression is revealed to be an independent prognostic factor for overall survival (OS) of NSCLC patients (n = 220, P = 0.014, hazard ratio (HR) = 0.816). In particular, SOX30 is a favorable and independent prognostic factor in one main subtype of NSCLC, lung adenocarcinoma (ADC) patients (n = 150, P = 0.000, HR = 0.405), but not in another main subtype of NSCLC, squamous cell carcinoma patients. Furthermore, high expression of SOX30 represents a favorable and independent factor for the prognosis of ADC patients at clinical stage II (P = 0.013), with positive lymph node (P = 0.003), at histological grade 2 (P = 0.000) or grade 3 (P = 0.025). In summary, SOX30 expression represents an important prognostic factor for survival time in ADC patients.