This dissertation examines the Saudi undergraduate educational environment, exploring relationships among teacher support, basic psychological needs satisfaction and frustration, academic motivation, and GPA. The study investigates whether basic psychological needs mediate the relationship between teacher support and academic motivation, utilizing a structural equation model with 312 Saudi undergraduate students. The findings reveal a positive relationship between teacher support and basic psychological need satisfaction, influencing academic motivation. Interestingly, GPA did not correlate with other variables. Various models were tested, resulting in two sets of models that underscore the significant role of basic psychological needs as mediators in shaping the relationship between teacher support and academic motivation among Saudi undergraduate students. The results highlight intriguing findings regarding the relationship between basic need satisfaction and academic motivation within the Saudi sample. One practical implication of this study is to encourage educators to raise awareness about the significance of basic psychological needs in the Saudi undergraduate educational environment. The study also discusses limitations and provides future research recommendations to enrich the understanding of Saudi undergraduate student motivation. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]