Metal sulfides are usually prepared by heating mixtures of the two elements, but in the case of scandium, this method yields scandium monosulfide, ScS. ScS can be prepared by heating scandium(III) oxide under flowing hydrogen sulfide in a graphite crucible to 1550 °C or above for 2–3 hours.  The crude product is then purified by chemical vapor transport at 950 °C using iodine as the transport agent.
:ScO + 3HS → ScS + 3HO
Scandium(III) sulfide can be prepared by reacting scandium(III) chloride with dry hydrogen sulfide at elevated temperature:
:2 ScCl + 3 HS → ScS + 6 HCl