Parental school involvement (PSI) is a multidimensional construct that significantly influences children's academic adjustment and overall development. However, inconsistencies persist in its definition and measurement, with researchers operationalizing PSI through a varied of parental activities. This study aimed to (1) identify PSI instruments and their theoretical models and (2) evaluate their psychometric properties. Following PRISMA guidelines (PROSPERO ID CRD42023451091, registered August 2023), this systematic review examined six databases (Web of Science, ERIC, MEDLINE, Psychology and Behavioral Sciences Collection, PsycArticles, and PsycInfo), analyzing quantitative studies from 2000 to 2024. Inclusion criteria encompassed instruments designed for parents, teachers, or children aged 6-15 and published in peer-reviewed journals in English, Portuguese, Spanish, or French. From an initial pool of 490 records, 38 studies were included, yielding 43 instruments: 23 for parents, 15 for children, and 5 for teachers. Seven instruments followed Epstein's model, while nine followed the Hoover-Dempsey and Sandler framework, underscoring the prominence of these theoretical approaches. The study quality, assessed with MMAT, was generally moderate to high. Despite an exhaustive search effort, it is possible that some relevant instruments were not identified. Nevertheless, this review advances the understanding of PSI operationalization, promotes more consistent and replicable assessments, enhances alignment between instruments and study objectives, and strengths the validity of findings derived from these tools.