IntroductionApproximately 12.3% of mothers experience childbirth-related post-traumatic stress symptoms (CB-PTSS). However, evidence-based interventions to treat CB-PTSS are lacking. Intrusive memories (IM), a key CB-PTSS, are distressing and can trigger other PTSS by reliving the traumatic event. Emerging evidence shows that a behavioural intervention involving a visuospatial task (BI-VT) can reduce the number of IM and PTSS, supposedly by interfering with the reconsolidation of the trauma memory. This study aims to test the efficacy of a single-session BI-VT targeting IM to reduce the number of childbirth-related (CB-)IM and PTSS, in comparison to a waitlist control group (WCG).Methods and analysisIn this multicentre, single-blind, randomised controlled trial being undertaken at one regional and one university hospital in Switzerland, 60 participants will be allocated to the Immediate Intervention Group (IIG), receiving the immediate intervention on day 15, and 60 participants to the WCG receiving the delayed intervention on day 30. All participants will report their CB-IM during the 2 weeks preimmediate and postimmediate intervention in diaries. The IIG will additionally report their CB-IM over weeks 5 and 6 postimmediate intervention. Self-report questionnaires will assess CB-PTSS at 2 weeks preimmediate and postimmediate intervention in both groups, and at 6 weeks postimmediate intervention in the IIG. A feedback questionnaire will evaluate the intervention acceptability. The primary outcome will be group differences in the number of CB-IM between the 2 weeks preimmediate and postimmediate intervention. Secondary outcomes will be CB-PTSS at 2 and 6 weeks postimmediate intervention, the number of CB-IM at weeks 5 and 6 postimmediate intervention, and intervention acceptability.Ethics and disseminationEthical approval was granted by the Human Research Ethics Committee of the Canton of Vaud (study number 202200652). Participants will provide an informed consent before study participation. Results will be presented in peer-reviewed journals and at conferences.Trial registration numberNCT05381155.