In the presented study, Pt(II) complex including 4-Bromo-2,6-bis-hydroxymethyl-phenol (BBHMP) and nicotinamide (NA) was synthesized and structurally analyzed by using spectral and thermal analysis methods. The BBHMP and its Pt(II) complex involving BBHMP and NA were investigated for their antimicrobial, cytotoxicity, gen expression and antioxidant properties. The antimicrobial activity results showed that the platinum complex displayed moderate antibacterial and antifungal activities. The cytotoxicity of the BBHMP and platinum complex were determined against human prostate (DU145) and breast (MCF7) cancer cell lines by applying MTT assay. Cytotoxicity results suggest that the Pt(II) complex exhibited moderate cytotoxicity against growth of used cancer cell lines when compared with the reference drug cisplatin. Gen expression results proved that Pt(II) complex is a special bioactive chemical constituent and potential anticancer agent. In addition, the complex demonstrated important antioxidant activity.