Background: Studies indicate the immediate early response gene 3 (IER3) is involved in many biologicalprocesses. Recently, it was discovered that IER3 plays an important role in tumorigenesis and tumor progression.Thus it may be a valuable biomarker in tumor. This study was designed to investigate the expression status ofIER3 in primary hepatocarcinoma (PHC) and correlation with clinicopathological parameters. Materials and Methods: Real-time PCR was performed to evaluate the expression levels of IER3 in 62 pathologically diagnosedhuman PHC specimens. Results: A statistically significant association was disclosed between the expression ofIER3 and P53 mutant protein (short for P53), Ki-67, EGFR and the biggest diameter, differentiation grade oftumor. Conclusions: This work is the first to shed light on the potential clinical usefulness of IER3, as an efficienttumor biomarker in PHC.