Studies for the past 30 years have stated that the longer individuals participate in sport, the less able they are to morally reason about issues in sport. Some argue that the way competition is taught or modeled affects the ability to treat others fairly, honestly, and justly both on and off of the playing fields. However, these studies are either anecdotal or report data through one shot individual studies of students by grade level. Therefore, the purpose of this study was to examine student moral reasoning over a four year high school competitive experience. All freshman students in a large urban high school were assessed using the Hahm-Beller Values Choice Inventory (HBVCI). The HBVCI, a 21 question tool, is valid and reliable for measuring moral reasoning in sport (Chronbach Alphas .77 - .88). In the last month of their high school career, all students again took the HBVCI. Test scores were matched (n = 275 of 431 = 65%). A repeated measures ANOVA was run to detect differences by Time and the main factors of Gender and Status (nonathlete, team, individual sport). Student moral reasoning scores significantly declined from freshman (M=70.23,SEM=.78) through senior (M=65.06,SEM=.86) year. Wilks’ Lambda (F [1,269] = 38.79, p<.000). Between subjects ANOVA was run to detect differences by status. After a significant F, Fishers LSD posthoc was run: team sport athletes scored significantly lower (M=65.55, SEM=.74) than nonathletes (M=68.82,SEM=1.39) and individual sport athletes (M=68.55, SEM=1.46) (F[2,269] = 3.27, p<.04). Males scored (M=63.01, SEM=1.05) significantly lower than females (72.22,SEM .94) (F[1,269] = 42.23, p<.000). While previous one-shot studies found that athletes scored significantly lower than general students in moral reasoning, no significant difference was found in general students’ freshman versus senior class moral reasoning. As one of the first studies to follow one group over four years, this study shows significant results that some facet of the competitive high school experience negatively affects both general student and student athlete abilities to use positive moral reasoning. Keyword(s): athletics/sports, high school issues, standards and ethics