Preparation and optical characterisation of Erbium doped KY₃F₁₀ single crystals are reported. The crystals were grown using the Czochralski pulling technique. The single phase was controlled by X-ray diffraction analysis. Room temperature optical spectra were recorded between 200 and 1600 nm. They were used to fit the three phenomenological Judd-Ofelt (JO) parameters Ω_t (t = 2, 4, 6). The emission transition probabilities, branching ratios and radiative lifetimes are then deduced. The possibility to use such material for laser emissions is discussed.