The synthesis and characterization of two new bis-cyclometalated compounds [Ir(ptpy)(2)(kappa N-2-terpy-C6H4Cl-p)]PF6 [terpy-C6H4Cl-p=4'-(4-chlorophenyl)-2,2':6',2''-terpyridine, (1)], and [Ir(ptpy)(2)(kappa N-2-terpy-Cl)]PF6 [terpy-Cl=4'-chloro-2,2':6',2''-terpyridine, (2); ptpy=2-(p-tolyl)pyridinato)] are described. The molecular structures of compounds 1 and 2 in the crystal were determined by single-crystal X-ray diffraction. 1 crystallized from dichloromethane/methanol/iso-hexane in the monoclinic space group P2/(n) and 2 from the same mixture of solvents in the triclinic space group P(-)1. Photophysical investigations on 1 and 2 revealed broad unstructured luminescence in the red spectral region with the emission maxima in dichloromethane at 620 and 630 nm respectively. To explore cytotoxic properties of compounds 1 and 2, a colorimetric assay (MTT assay) against prominent cancer cell lines, MCF-7 and HT-29, was performed. The determined IC50 values are in the low micromolar range (2-3 mu M). In comparison to cisplatin, the tested complexes 1 and 2 exhibit up to >20-fold (MCF-7) and >40-fold (HT-29) increase in biological activity.