Polystannanes are characterized by a main chain which consists of covalently bound tin atoms. Characteristic absorption maxima in UV-vis spectra of poly(dialkylstannane)s are due to σ-delocalization and of poly(diarylstannane)s to σ–π delocalization. Poly(diorganostannane)s are thermally stable with decomposition commencing above 200 °C. Poly(dialkylstannane)s can show liquid-crystalline behavior around room temperature. They can be oriented by various procedures, whereby orientation of the polystannane main chain depends on the orientation procedure and the length of the alkyl side groups. Some of the oriented systems showed a pronounced dichroism. Polystannanes degrade under the action of light, in particular when in solution.