Objective To observe whether all trans retinoic acid (ATRA) can promote the apoptosis effect of tumor necrosis factor related apoptosis induced ligand (TRAIL) on various pancreatic cancer cells. Methods The pCA13 plasmid carrying TRAIL gene was transfected into three types of pancreatic cancer cell SW1990, Patu8988 and Bx-PC3 respectively. ATRA or equivalent solvent was added after 24 h of transfection. The cell viability was measured by the methyl thiazolyl tetrazolium(MTT) method, apoptosis rates and the expression of TRAIL receptor R1 and R2 were detected by flow cytometry, and the apoptosis was observed by terminal deoxynucleotidyl transferase(TdT) mediated dUTP nick end labeling (TUNEL) and Hoechst double staining and transmission electron microscopy. Results The cell viability of the TRAIL+ATRA group was significantly inhibited compared to the group without ATRA (P<0.05). The result of the flow cytometry showed that ATRA significantly promoted cell apoptosis compared with the group without ATRA(P<0.05). Apoptosis was observed by transmission electron microscopy after TUNEL and Hoechst double staining. However, there was no significant difference in expression of TRAIL-R1 and R2 between the TRAIL+ATRA group and the non-ATRA group(P>0.05). Conclusions ATRA can promote the apoptosis of TRAIL on various pancreatic cancer cells, and its mechanism is not related to the up-regulation of TRAIL-R1 and R2.