Trachyspermum copticum is one of the most important Iranian Apiaceae species which is widely distributed in the northern region of Iran. In this study, chemical compounds, anti-tumor and antibacterial activities of T. copticum essential oil were evaluated. The essential oil obtained by Clevenger apparatus and then the chemical composition was analyzed by GC-MS. Antibacterial activity of essential oil was evaluated by well diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the macrodilution method. An MTT cytotoxicity assay was employed to test effects of the essential oil on each human breast cancer cell lines. The GC-MS spectrums showed 9 major compounds, in which the highest chemical composition was related to thymol (42.16%), g-Terpinene (31.49%) and p-cymen (23.29%) compounds. T. copticum essential oil showed good antitumor activity on SKOV3 and MDA-MB-231cell lines (IC₅₀ of 208.13.6µg/ml and IC₅₀ 236.16µg/ml, respectively). It also showed good activity against to tested bacteria. The MIC and MBC values of the bacterial strains sensitive to the essential oil were in the ranges of 0.4 to 3.1 mg/ml and 0.4 to 6.25 mg/ml, respectively. Because of the high concentration of phenolic compounds, the essential oil from T. copticum exhibited antimicrobial and antitumor activities, which deserve further research into the chemoprevention and treatment of human ovary and breast cancers as well as infectious diseases.