To evaluate serum nerve growth factor (NGF) as a marker in predicting effectiveness of 125I seed implantation in advanced pancreatic carcinoma. A total of 45 patients (30 males/15 females with mean age of 52.07±8.43 years) diagnosed with advanced pancreatic adenocarcinoma (PCa) between January 2011 to May 2014 were enrolled as PCa group in this study. Tumors were categorized as at least stage III with unresectionable condition by the TNM standard. The average tumour shortest diameter was 37.54±13.84 mm (18.50-71.20 mm). NGF level in serum before 125I seed implantation and in tumor tissue resected during surgery was measured by ELISA. After treatment, CT Scan was used to serially monitor the diameters of the tumour monthly for 6-month follow-up. RECIST was applied to evaluate the efficacy. Predictive value of serum and tumour derived NGF was evaluated based on ROC curve chart. We found that the serum NGF level was significantly increased in PCa patients (775.60 ± 250.97 pg/ml) compared to the healthy control group (35.03 ± 25.36 pg/ml), after age and gender adjustment. In the PCa group, the serum NGF level positively correlated with that from loci tumor tissue (r=0.487). The serum NGF level was compared between the effective group (537.42 ± 122.61 pg/ml) and noneffective group (883.17 ± 217.79 pg/ml), and significant difference was detected (p<0.0001). Patients with lower serum NGF level had good response to the 125I seeds implantation. Taking cut-off at 649.59 pg/ml, 85.70% specificity and 90.30% sensitivity were achieved by ROC. Area under the Curve of serum NGF was 0.945, standard deviation was 0.032, 95% confidence interval was 0.882-1.000. The level of serum NGF could be a referential index to predict the therapeutic efficacy of 125I seed implantation treatments in advanced pancreatic adenocarcinoma.