Background: Intellectual disability (ID) is associated with polypharmacy particularly off-label psychotropics for "challenging behaviour." NHS England introduced the "stopping over medication of people with a learning disability (LD), autism or both" (STOMP) initiative. As ID services are a professionally diverse group, it is important to know whether teams have suitable knowledge to deliver STOMP. The impact of delivering bespoke STOMP training was evaluated. Methods: A 21-item multiple-choice questionnaire was distributed to three specialist ID teams in the south-west of England. Current best practice and national guidance knowledge on psychotropic medication use in ID were assessed. One team received bespoke training covering the content of the questionnaire prior to completion. Results: Survey participation was 44% (21/48) by the trained team, 34% (15/44) and 70% (7/10) in the untrained teams. The trained team participants scored over 80% on 19/21 questions compared to 15/21 and 16/21 in the untrained teams. Subspeciality analysis of pooled data (n = 43) showed nursing scored more than 80% on 16/21 questions, psychology 15/21 and allied health professionals (AHPs) 19/21. Nursing and psychology both reported STOMP to be a priority. Majority responded "yes" to potentially being involved in STOMP. Conclusions: Better STOMP knowledge and understanding of best practice and guidelines are associated with training. Nursing and psychology are essential to STOMP delivery but scored lower than AHPs. We recommend semi-structured STOMP training developed locally with national underpinnings for all specialist ID teams, particularly focussed on front-line staff directly involved in the management of challenging behaviour.