Abstract: The aim of this study was to determine knowledge, attitudes and practices on hydration and fluid replacement among endurance sports athletes in Universiti Kebangsaan Malaysia (UKM). This study was also to identify the relationship among these parameters. A total of 80 UKM endurance sports athletes were involved in this study. Data collection was conducted using anthropometric measurements and questionaires. Anthropometric measurements included height, weight and body composition using bioimpedance method. Socio-demographic information, hydration knowledge, attitudes and practices were collected using questionnaires. The mean age of athletes was 22.0±2.6 years. The mean score for knowledge, attitudes and practices of subjects towards hydration was 74.1±10.1, 60.9±20.3 and 76.1±14.6%, respectively with higher scores indicating positive hydration knowledge, attitudes and practices. Knowledge did not show a significant correlation with practices (r = 0.126, p>0.05) but significant correlation with attitudes (r = 0.285, p<0.05). However, attitudes showed a positive significant correlation with practices (r = 0.421, p<0.01). Most athletes correctly answered the general hydration questions on the survey but under the assumption regarding usage of salt tables to avoid hydration and thirst is the best indication for dehydration. They are also lacked knowledge regarding appropriate use of sports drinks. The mean score of knowledge, attitudes and practices for subjects with previous nutrition education was not significantly different compared to subjects without nutrition education (p>0.05). Only the mean score of knowledge was significantly different between male and female (p<0.05). Improvement of hydration knowledge, attitudes and practices is the most relevant step to ensure the hydration level of athletes is at its optimum level during training and competition. The results of this study identify specific areas of education for athletes with regard to hydration.