This study is part of a large-scale project focused on "Qatari students' Interest in, and Attitudes toward, Science" (QIAS). QIAS aimed to gauge Qatari student attitudes toward science in grades 3-12, examine factors that impact these attitudes, and assess the relationship between student attitudes and prevailing modes of science teaching in Qatari schools. This report details the development and validation of the "Arabic-Speaking Students' Attitudes toward Science Survey" (ASSASS), which was specifically developed for the purposes of the QIAS project. The theories of reasoned action and planned behavior (TRAPB) [Ajzen, I., & Fishbein, M. (2005). The influence of attitudes on behavior. In D. Albarracín, B. T. Johnson, & M. P. Zanna (Eds.), "The handbook of attitudes" (pp. 173-221). Mahwah, NJ: Erlbaum] guided the instrument development. Development and validation of the ASSASS proceeded in 3 phases. First, a 10-member expert panel examined an initial pool of 74 items, which were revised and consolidated into a 60-item version of the instrument. This version was piloted with 369 Qatari students from the target schools and grade levels. Analyses of pilot data resulted in a refined version of the ASSASS, which was administered to a national probability sample of 3027 participants representing all students enrolled in grades 3-12 in the various types of schools in Qatar. Of the latter, 1,978 students completed the Arabic version of the instrument. Analyses supported a robust, 5-factor model for the instrument, which is consistent with the TRAPB framework. The factors were: Attitudes toward science and school science, unfavorable outlook on science, control beliefs about ability in science, behavioral beliefs about the consequences of engaging with science, and intentions to pursue science.