The purpose of this study was to try and further understanding of the relationship between perfectionism and performance, especially among an athlete population. Specifically, the aim of this study was to understand the relationship between a college baseball player's levels of perfectionism and general state of mental health, and their performance. Perfectionism was measured on three levels (Self-Oriented Perfectionism, Other-Oriented Perfectionism, Socially-Prescribed Perfectionism) using the Multidimensional Perfectionism Scale (MPS); general mental health was measured using the General Health Questionnaire-9 (GHQ-9); and baseball player performance was measured using the On-Base Plus Slugging statistic. Due to the 2020 college baseball season being ended prematurely because of the COVID-19 pandemic, this study was limited by a shortage of information related to baseball player's performance. Therefore, two statistical analyses were performed on the data gathered. The first, integrating usable performance data, displayed no relationship between perfectionism, general mental health, and performance [R[superscript 2] = .074, R[superscript 2][subscript adj] = -.003, F (4, 48) = .955, p = .441]. The second analysis, consisting of only perfectionism and general mental health scores, displayed a small but significant positive correlation between perfectionism and general mental health [R[superscript 2] = .181, R[superscript 2][subscript adj] = .151, F (3, 82) = 6.037, p = .001]. A discussion of the consistency of findings with prior research, as well as limitations follows. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]