This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

The primary objective of this review is to investigate the clinical efficacy of different serotonin receptor antagonists (5‐HT3 RAs) in the control of acute and delayed emesis induced by highly emetogenic chemotherapy.

The secondary objectives are to examine eligible studies for information on adverse events and to assess if there are important differences in the adverse events caused by the different anti‐emetic agents.