The purpose of this study was to describe a Spanish protocol that includes reading, writing, and math Curriculum-Based Measures (CBMs) aimed at early detection of students at risk of presenting learning disabilities (LD). Early identification of LD is a critical component of the Response to Intervention (RtI) model. In early grades, the screening of foundational skills mentioned above can provide a data-based guideline for identifying students requiring a more intensive response-based intervention before starting elementary school. We designed different CBMs based on indicators of basic early reading, writing, and math skills [Indicadores de Progreso de Aprendizaje en Lectura, Escritura y Matemáticas, IPAL, IPAE, and IPAM respectively] that aim to fulfill the twofold objective of universal screening and evaluation of the Spanish students' progress. For reading, IPAL includes alphabetic principle, phonological awareness, concepts about print, and riddles in kindergarten. In first and second grades, IPAL includes alphabetic principle, nonsense words fluency, maze sentences, and oral reading fluency. In addition, it includes phonemic segmentation for first grade and prosody for second grade. For writing, IPAE includes copying letters, writing allographs, dictated letters, dictated words with arbitrary spelling, dictated words with rule-based spelling, dictated nonsense words, dictated sentences, writing sentences, and writing a story for first-third grades. Finally, for math, IPAM includes number comparison, missing number, number identification, quantity array, and counting aloud for kindergarten, and number comparison, multi-digit computation, missing number, single-digit computation, and place value for first-third grades.