This dissertation offers a Cognitive Grammar-based approach to teaching cases to L2 German and Russian students and examines the impacts of various methods of case instruction in beginning German and Russian language classes. A CG-based explanation of cases was already proposed by some CG theorists (i.e., Langacker 1987, 1991; Smith 1987, Janda 2002), but little research has been conducted on the practical side of such theories. By examining the effects of the CG-based instruction of cases in the test groups and comparing the results of the test and control groups, the dissertation sought to discover whether the CG-based explanation of cases results in improved case acquisition. The dissertation's theoretical component consists of the description of the role semantics and cognitive features of the German and Russian grammatical cases. While most current textbooks offer the L2 learners traditional, ineffective Latin- and Greek-based models, this work provides a CG-based semantic characterization of the German and Russian case systems and offers a simplified CG-based version of case explanation, providing diagrams to evoke cognitive images in students' minds. The study's practical value consists in the experimental data on the acquisition of cases by L2 learners of German and Russian. The proposed explanation of cases was applied in test groups, and the results gathered after one year of instruction were compared to those in the control groups. Data for this research have been collected from the beginning German and Russian language classes at the University of California, Davis and the University of Alabama, Tuscaloosa with a total of 43 participants in German and 22 participants in Russian. This dissertation has shown that the CG-based explanation of cases had an overall positive effect on learners of German and Russian; particularly, that students, who have been exposed to the CG presentation of cases, demonstrate better accuracy in using cases in practice. [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.]