BackgroundThe Portuguese Physical Literacy Assessment (PPLA) is a novel tool to assess high-school students’ (grade 10–12; 15–18 years) Physical Literacy (PL) in Physical Education (PE); inspired by the four domains of the Australian Physical Literacy Framework (APLF), and the Portuguese PE syllabus. This paper describes the development, content validation, and pilot testing of the PPLA-Questionnaire (PPLA-Q), one of two instruments in the PPLA, comprised of modules to assess the psychological, social, and part of the cognitive domain of PL.MethodsDevelopment was supported by previous work, analysis of the APLF, and literature review. We iteratively gathered evidence on content validity through two rounds of qualitative and quantitative expert validation (n = 11); three rounds of cognitive interviews with high-school students (n = 12); and multiple instances of expert advisor input. A pilot study in two grade 10 classes (n = 41) assessed feasibility, preliminary reliability, item difficulty and discrimination.ResultsInitial versions of the PPLA-Q gathered evidence in favor of adequate content validity at item level: most items had an Item-Content Validity Index ≥.78 and Cohen’s κ ≥ .76. At module-level, S-CVI/Ave and UA were .87/.60, .98/.93 and .96/.84 for the cognitive, psychological, and social modules, respectively. Through the pilot study, we found evidence for feasibility, preliminary subscale and item reliability, difficulty, and discrimination. Items were reviewed through qualitative methods until saturation. Current PPLA-Q consists of 3 modules: cognitive (knowledge test with 10 items), psychological (46 Likert-type items) and social (43 Likert-type items).ConclusionResults of this study provide evidence for content validity, feasibility within PE setting and preliminary reliability of the PPLA-Q as an instrument to assess the psychological, social, and part of the cognitive domain of PL in grade 10 to 12 adolescents. Further validation and development are needed to establish construct validity and reliability, and study PPLA-Q’s integration with the PPLA-Observation (an instrument in development to assess the remaining domains of PL) within the PPLA framework.