Breast and esophagus cancer are the most aggressive and prominent causes of death worldwide. In addition, these cancers showed resistance to current chemotherapy regimens with limited success rates and fatal outcomes. Recently many studies reported the significant cytotoxic effects of phenolic and terpene fractions extracted from various Prunus species against different cancer cell lines. This suggests the probability to be a candidate as an alternative or adjuvant to the current chemotherapeutic regimens. The study aimed to evaluate the cytotoxicity of phenolic and terpene fractions extracted from Iraqi Prunus arabica on breast (AMJ-13) and esophagus (SK-GT-4) cancer cell lines by using the MTT assay. Analysis using Chou-Talalay method performed to assess the synergistic effect between the extracted fractions and chemotherapeutic agent (docetaxel). Moreover, HPLC analysis has been conducted for the quantitative determination of different bioactive molecule of both phenolic and terpene fractions in the extract. According to the findings, the treatment modalities significantly decreased cancer cell viability of AMJ-13 and SK-GT-4 and had insignificant cytotoxicity on the normal cells (normal human fibroblast cell line) (all less than 50% cytotoxicity). Analyzing with Chou-Talalay showed a strong synergism with docetaxel on both cancer cell lines (higher cytotoxicity even in low concentrations) and failed to induce a cytotoxicity on the normal cells. Important flavonoid glycosides and terpenoids were detected by HPLC in the particularly ferulic acid, catechin, chlorogenic acid, B sitosterol, and campesterol. In conclusion, the extracted fractions selectively inhibited the proliferation of both cancer cell and showed minimal cytotoxicity on normal cells. Thus, the study suggested the possible natural source of selected fractions as breast and esophagus cancer drugs