Purpose Adequate nutrition knowledge forms the foundation for optimal physical health and performance. In Lebanon, there are limited studies on the effect of nutrition knowledge on the athletes’ performance. This study aims to evaluate university athletes’ nutrition knowledge status and to identify the factors predicting athletes’ performance. Design/methodology/approach A cross-sectional survey was conducted among 384 university student-athletes, using a validated tool with modifications (Furber et al., 2017) to assess nutrition knowledge. The modified questionnaire includes seven subsections (vitamins and minerals, general nutrition, fluid, fat, carbohydrate, protein and sporting performance). Further, anthropometric measurements were taken; body composition was determined by the bioelectrical impedance analysis method. Handgrip strength, as an indirect measure of athlete performance, was assessed with the hand dynamometer. To measure the existence and degree of significance among different variables, Pearson correlation coefficients, χ2 and linear regression were used. Findings The health group had a higher level of nutritional knowledge, compared with the non-health group. The overall mean sports nutrition knowledge score for the student-athletes was 63.54%, which was considered inadequate sports nutrition knowledge (mean < 75%). Further, athletes’ performance was significantly predicted by the resting metabolic rate, lean muscle mass and weight. Originality/value The findings may help the university administration to implement a nutrition education program for athletes enrolled in non-health majors. Information gained serve to help dietetics professionals in Lebanon refine education strategies and sports clubs in universities to start to budget for hiring dietitians.