Purpose: The study was meant to investigate the motivational set-up among high school students of English. Design and Methodology: The design of the study was quantitative and a Likert scale format questionnaire was used to collect data from 241 high school students of English in Tunisia. The structural equation modeling approach was used to analyze data and specify a model of EFL motivation. Findings and Originality/value: Although all the variables considered in the study contributed to specifying the obtained model of motivation, these variables differentially feed in one another and directly and indirectly affect the criterion measures of motivation. Social attitudes proved to be the variable with the largest effect on motivational intensity and expectancy of success, as indirect criterion measures. In contrast, intrinsic orientation, attitude towards L2 and L2 learning experience, and self-efficacy proved to have the largest effects on achievement, as a direct measure of motivation. The present study proved that only an eclectic theoretical approach can allow for grasping the full picture of L2 motivation. It also showed that motivational variables differently as well as direclty and indirectly affect the criterion measures of L2 motivation. Finally, the study established that the relationship between self-efficacy, attitudes, and orientations and the indirect criterion measures of L2 motivation is different from that between the same variables and achievement, as a direct criterion measure.