Background: Efficiency of both photodynamic and boron-neutron capture (BNCT) anticancer therapies depends on the properties of the used photo- and neutronsensitizer. We report on the synthesis and properties of the advanced photo- and neutronsensitizer designed as a conjugate of chlorin e6 with iron bis(dicarbollide) nanocluster. Results: The conjugate is shown to accumulate efficiently in rat glioblastoma C6 cells delivering >109 boron atoms per cell and thus meeting requirements for BNCT agents, to provide photoinduced 50% death of C6 cells at 35 ± 3 nM, to be not toxic for cells without activating stimulus. Conclusions: The conjugate is a prospective theranostic agent for photodynamic, BNCT and fluorescent diagnostics of tumors.