It is a white to yellow solid which rapidly absorbs water on exposure to moist air to form a hexahydrate, DyCl3·6H2O.

Simple rapid heating of the hydrate causes partial hydrolysis[2] to an oxychloride, DyOCl.

[3][4][5] These methods produce (NH4)2[DyCl5]: The pentachloride decomposes thermally according to the following equation: The thermolysis reaction proceeds via the intermediacy of (NH4)[Dy2Cl7].

Treating Dy2O3 with aqueous HCl produces the hydrated chloride DyCl3·6H2O, which cannot be rendered anhydrous by heating.

Instead one obtains an oxychloride:[4] Dysprosium(III) chloride is a moderately strong Lewis acid, which ranks as "hard" according to the HSAB concept.