The present study was carried out to investigate anti-tumoral effects of Anandamide (AEA) in luminal A breast cancer cell line MCF-7. Cell viability was measured by MTT assay and cell index was measured by xCelligence DP analyzer system. The Feulgen method was used to determine the mitotic index parameter, and the 3 H-Thymidine method was used to determine the labeling index parameter. The apoptotic index parameter was determined using a fluorescent dye DAPI. The results of this study showed that 25 µM Anandamide concentration was the optimum concentration for MCF-7 cells. While this concentration decreased the proportion of cells in the mitotic phase and synthesis phase, it increased the proportion of apoptotic cells.