A cyan dye-donor element which gives good printed images to a thermal-transfer sheet and a thermal-transfer sheet comprising a substrate sheet and a layer containing said cyan dye-donor and being laid on one side of the substrate sheet are provided. The cyan dye-donor element comprises cyan dyes dispersed or dissolved in a polymeric binder wherein said cyan dyes comprise: ##STR1## wherein R.sub.1 and R.sub.2 each represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group; at least one dye represented by the following formula (II): ##STR2## wherein R.sub.3 and R.sub.4 each represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group which may be substituted, and R.sub.5 represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group; and at least one dye selected from the group consisting of dyes represented by the following formula (III): ##STR3## wherein R.sub.6 and R.sub.7 each represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group which may be substituted, R.sub.8 represents a hydrogen atom, a C.sub.1 -C.sub.6 alkyl group which may be substituted, an alkoxy group which may be substituted or an acylamino group which may be substituted and R.sub.9 represents a hydrogen atom, a C.sub.1 -C.sub.6 alkyl group which may be substituted or an aryl group which may be substituted, dyes represented by the following formula (IV): ##STR4## wherein R.sub.10 represents a hydrogen atom, a C.sub.1 -C.sub.6 alkyl group which may be substituted, an aryl group which may be substituted or a cyclohexyl group, R.sub.11 -R.sub.13 each represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group which may be substituted, and R.sub.14 represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group which may be substituted or an alkoxy group which may be substituted, and dyes represented by the following formula (V): ##STR5## wherein R.sub.15 and R.sub.16 each represents a hydrogen atom or a C.sub.1 -C.sub.6 alkyl group which may be substituted.