A benzodiazepine derivative of formula (I), or a pharmaceutically acceptable salt thereof, wherein (a) R.sup.1 is --CH.sub.2 CHOH(CH.sub.2).sub.a R.sup.4 or a ketone group --CH.sub.2 CO(CH.sub.2).sub.a R.sup.5 in which a is 0 or 1 and R.sup.4 and R.sup.5 are selected from alkyl and cycloalkyl groups and saturated heterocyclic groups optionally substituted at a hetero-atom; (b) R.sup.2 and R.sup.3 are independently selected from aromatic carbocyclic and heterocylic residues; and (c) W and X are selected independently from halogen and hydrogen atoms and alkyl and alkoxy groups. These compounds are gastrin and/or CCK-B receptor antagonists. ##STR1##