This paper describes the validation of the Foundational Learning Skills (FLS) module, a newly developed instrument in the Multiple Indicator Cluster Surveys (MICS). The focus of this study is the concurrent validity of the FLS instrument, which was administered to children aged 7 to 14 in Kenya, along with the Early Grade Reading Assessment (EGRA) and Early Grade Mathematics Assessment (EGMA) tools. Evidence on the reliability of the instrument – such as inter-rater reliability and Cronbach’s alpha – was also obtained.