Adequate hydration is critical for optimal performance and health. Fluid requirements of collegiate athletes are unique due to training and competition, travel, school schedules, and stressors common in college environments. Inattention to these factors may contribute to suboptimal hydration. Importantly, loss of 1-2% of body weight by dehydration can impair physical and cognitive performance. As such, development of valid and reliable tools to assess hydration status in collegiate athletes is needed. The purpose of this study was to assess the validity of urine color (UC) as a measure of hydration status in collegiate athletes. A secondary purpose was to evaluate the utility of indexes of hydration status for UC and urine specific gravity (USG) established by the American College of Sports Medicine (ACSM) and the National Athletic Trainers' Association (NATA). To address this, 62 NCAA Division I collegiate athletes provided a urine sample ≤30 minutes of exercise for UC self-assessment (UCsub) and experimenter-assessment (UCres) using the UC chart developed by Armstrong et al. (1994) and for USG measurement via refractometry (1). Habitual dietary intake was assessed by 24-hr recalls. There was a significant positive correlation between USG and both UCsub (r=0.679, p<0.001) and UCres (r=0.772, p<0.001). In addition, the USG based on UC was inconsistent with hydration/dehydration categories established by ACSM and NATA. These findings suggest that UC, even when self-assessed by the athlete, is a valid method for assessing hydration status in NCAA division I college athletes. However, some modification of ACSM and NATA hydration categories may be warranted. 1. Armstrong LE, Maresh CM, Castellani JW, et al. Urinary indices of hydration status. Int J Sport Nutr. 1994;4(3):265-279. http://www.ncbi.nlm.nih.gov/pubmed/7987361. Accessed October 26, 2016. / Master of Science / Staying well hydrated is important for athletes’ health and to help them perform at their best. College athletes fluid needs are unique because of their training and competition schedules, class schedules, frequent travel, and emotional stress that is common for college students. Without conscious efforts to consume enough fluid during the day, athletes may not be well hydrated. Small decreases in body weight from dehydration can result in negative consequences for physical and mental performance. This is why it is important to develop tools that can accurately and consistently determine how hydrated athletes are. The purpose of this study was to see if urine color could accurately determine if college athletes were well hydrated or dehydrated. Also, the usefulness of hydration categories for urine color and urine specific gravity (USG) from the American College of Sports Medicine (ACSM) and the National Athletic Trainers’ Association (NATA) were tested. Our study recruited 62 NCAA Division I college athletes. Participants provided a urine sample where researchers and participants determined the urine color of the sample based on a urine color chart and USG was measured (1). In addition, a list of all foods and beverage consumed by participants were recorded for three days. Our correlational analysis suggest that UC, even when self-assessed by the athlete, can accurately determine if NCAA division I college athletes are well-hydrated or not. In addition, our results suggest that some modification made be needed to the ACSM and NATA hydration categories.