[en] Hollow particles of barium titanate were obtained by a two-step process combining colloidal chemistry and solid-state reaction. BaCO₃ crystals (size ∼1 μm) suspended in a peroxy-Ti(IV) aqueous solution were coated with an amorphous TiO₂ shell using a precipitation process. Calcination of the BaCO₃-TiO₂ core-shell particles at 700 deg. C resulted in the formation of BaTiO₃ hollow particles (shell thickness of ∼70 nm) which retain the morphology of the BaCO₃ crystals. Formation of the cavity occurs because out-diffusion of the core phase is much faster than in-diffusion of the shell material. X-ray diffraction (XRD) and Raman spectroscopy indicate that the hollow particles possess a tetragonal ferroelectric structure with axial ratio c/a = 1.005. Piezoresponse force microscopy has shown strong piezoactivity and 180 deg. ferroelectric domains. The process described provides a general route to fabricate hollow ferroelectric structures of several compounds