<p>A rational approach was developed to the synthesis of new potential agents for photodynamic therapy and imaging of neoplasms based on cationic <i>meso</i>-arylporphyrins and a 2,2′:6′,2′-terpyridine derivative. The photophysical and photochemical properties of the new conjugates were studied and their biological activity was evaluated. Micelle-forming solubilizing agents based on the pluronic F-127 were found to stabilize the monomeric form of porphyrin. The dark and photoinduced toxicity of the micellar form of the conjugate was studied by the MTT assay. The half-maximal inhibitory concentration (IC₅₀) in the <i>Hep</i>-2 cell line (human laryngeal cancer cells) for photoinduced toxicity of the target compound was 0.35±0.12 µmol L⁻¹, which is 20 times higher compared to its dark toxicity. The accumulation of this conjugate in the <i>Hep</i>-2 cells was studied by flow cytofluorometry. The biological safety was assessed by the DNA-comet assay. The synthesized conjugate can be recommended for further <i>in vivo</i> biological assays.</p>