Students' creativity is an important focus globally and is interrelated with students' spatial abilities. Additionally, three-dimensional computer-assisted drawing (3D-CAD) overcomes barriers to spatial expression during the creative design process. Does 3D-CAD affect students' creative abilities? The purpose of this study was to explore the auxiliary effects of 3D-CAD applications on students' creative design capabilities and on students with different spatial abilities. A total of 349 students from a public senior high school in Taoyuan County, Taiwan, participated in the study. The study used a non-equivalent pretest and post-test quasi-experimental design. The key results from the study include the following: (1) students' spatial abilities were moderately correlated with their creative performance, especially their functional creativity; (2) the 3D-CAD applications enhanced students' creative performance, particularly with regard to aesthetics; and (3) in 3D-CAD applications, students with better spatial abilities were superior to those with relatively poor spatial abilities with regard to creative performance. Additionally, the effect sizes of novelty and aesthetics were stronger than that of functionality.