BackgroundsThe principal instructional leadership describes how school principals oversee the curriculum, instruction, and assessment. The main aims of the current study were translation and evaluation of the psychometric properties of the Principal Instructional Leadership Scale (PILS) in a Saudi Arabian population. MethodsThe translation and cross-cultural adaptation process has been conducted in five stages, including forward translation, translation synthesis, backward translation, expert committee, and pilot testing. Face, content, construct, and convergent validity were used to establish validity. Cronbach's alpha coefficient and McDonald's omega (Ω) were used for internal consistency. ResultsTo validate the PILS structure, the total sample (N = 724) was randomly split into two subgroups, each comprising 362 individuals, for Confirmatory Factor Analysis (CFA) and Exploratory Factor Analysis (EFA). Five factors obtained from EFA explain 71.07 % of the variance in PILS. The PILS encompasses domains of improving curriculum quality, teaching, and enhancing the effectiveness of adaptive learning, adding to the dimensions covered by previous instructional leadership measures. The five components show strong internal consistency (0.93 to 0.97). Both first-order and second-order CFAs confirmed the 5-factor model, meeting criteria (CFI > 0.91, GFI > 0.9, IFI > 0.9, RMSEA<0.05). All 21 items displayed suitable internal consistency (Cronbach's α > 0.8, McDonald's omega >0.7). Second-order average variance extracted validity (0.50) indicated PILS validity. Gender invariance analysis revealed no significant differences (∆CFI < 0.01, ΔRMSEA<0.01) in PILS structure between genders. ConclusionThe reliability and validity of the Arabic rendition of PILS are commendable, making it suitable for evaluating principal instructional leadership in Saudi Arabia.