100 Rials

Yemen's unification in 1990 created an immediate currency problem: the Yemen Arab Republic had used the Rial, the People's Democratic Republic of Yemen had used the Dinar, and the new Central Bank needed to consolidate both into a single system without triggering a collapse in public confidence. This note is part of the first unified series issued under that mandate. Thomas De La Rue handled the contract, as they had for both predecessor states.

The watermark is the sole mechanical security feature — modest by early 1990s standards, even for a low-denomination regional note.