The aim of the study was to quantify evidence of reduced Interpersonal Motor Synchrony in ASD-TD dyads. To this end, we systematically searched, selected and summarised studies from the literature. Then, we conducted a meta-analysis asking to which extent ASD-TD compared to TD-TD dyads synchronize at a motor level during interactions. We conducted a systematic review and meta-analysis on Interpersonal Motor Synchrony (IMS) in Autism. The materials here presented include: - *OSF.rproj* - the R directory to run the analyses - *df.csv* - the raw dataset used in the analysis - *df_info.csv* - the dataset including informations of each selected study - *prisma.csv* - the dataset used to compile the PRISMA flow diagram - *Script.R* - plain R code syntax to reproduce the analysis results (same reported in the paper) - *SupplementaryMaterials.Rmd* - RMarkdown file used to create the supplementary materials The preprint of this article can be found at: https://psyarxiv.com/a6pg4