The purpose of this study was to compare the biological effects as antimicrobial and antitumor activity and bioactive ingredients of two plants Iphonia mucronata and Conyza dioscorides which belong to the Asteraceae family. I. mucronata EtOAc extract exhibited promising antitumor activity against HELA (cervical), PC-3 (prostate), and HEP-2 (larynx) carcinoma cell lines with IC₅₀ values 24.60, 26.57 and 39.06 μg/ml, respectively. While C. dioscorides showed weak and moderate antitumor activity against the same cell lines. MeOH extracts of the two plants showed weak antitumor activity, also MeOH and EtOAc of C. dioscorides exhibited moderate and weak antibacterial activity against Proteus vulgaris, Bacillus subtilis and Escherichia coli, respectively. The total active constituents of the MeOH extract of both plants revealed higher concentrations than the EtOAc extract of all components except alkaloid content. The phenolic, flavonoid, and alkaloid constituents of I. mucronata were in higher concentrations than C. dioscorides while the saponins content of C. dioscorides was higher than I. mucronata whereas tannins content was similar for both plants. The major phenolic acids and flavonoid compounds investigated using HPLC of both plants were caffeic, ferulic acid, naringin, and luteolin for C. dioscorides and I. mucronata.