Background and objective It has been proven that neuron specific enolase (NSE) was one of the sensitive tumor markers for small cell lung cancer (SCLC). The aim of this study is to investigate the usefulness of serum NSE values as diagnostic and prognostic factors in patients with SCLC. Methods Serum NSE was detected by electrochemiluminescence method in 57 SCLC cases pre- and post-treatment. Survival curves were constructed using the Kaplan-Meier method and then compared using the Log-rank test. Results Pre-treatment serum NSE values are prognostic factors for overall survival of patients with SCLC. There was a statistically significant difference in the pretreatment NSE levels of patients who were at an extensive stage compared with the values of those patients who were at a limited stage (P<0.001). The rate of change between the pre- and post-treatment serum NSE levels was not related to the overall survival (P=0.084). Conclusion NSE is an ideal tumor marker for the diagnosis and assessment prognosis of SCLC.