Introduction: Choriocarcinoma is malignant cancer originating from placental trophoblast. The incidence of this cancer is estimated at 0.57-1.1 per 1000 births in the United States of America, Australia, Europe, and New Zealand. The rate is much higher in South East Asia and Japan with two occurrences per a thousand births. Telomerase activity is an important part of the apoptotic process. Increased telomerase activity will result in cellular immortality and poor prognosis in cancer. Vitamin A possess an essential role in cell proliferation and differentiation. One of the active metabolites of vitamin A is All-Trans Retinoic Acid (ATRA). Methods: In this study, we examined the role of ATRA against telomerase activity in choriocarcinoma cell. This cell was derived from BeWo cell line (ATCC CCL-98) and were given different doses of ATRA. Results: From this study, Choriocarcinoma cell that was given ATRA in dosage of 50μg/ml inhibit telomerase activity by extending the cycle time of 39.51±0.09, compared to the control group with a cycle time of 37.62±0.43. Cycle length change consistently with higher dose of ATRA. Conclusion: This study has proven that ATRA could inhibit telomerase activity by lengthening the cycle. Changes in the increase of ATRA doses in this experimental test need to be studied further on experimental animals, either administered as a single agent or as an addition to standard treatment of trophoblastic disease