To promote student "physical literacy," physical educators must teach and assess health-related fitness content knowledge (HRFK) and model healthy lifestyles. Individual HRFK is associated with lifetime physical activity (PA) and each may precede/predict both teaching and assessing of student HRFK. Purpose: The purpose of this study was to examine factors related to physical educators' teaching and assessment of student HRFK. Method: Physical educators (N = 796) representing each SHAPE America regional district completed a 33-item survey to determine their individual HRFK, weekly PA, and extent to which they teach (tHRFK) and assess (aHRFK) student HRFK. Results: Multiple regression was conducted to determine if tHRFK and aHRFK are predicted by teachers' individual HRFK, min/week of light, moderate, or vigorous PA, or any demographic variables. Overall, the tHRFK model was significant (F = 10.919, R[superscript 2] = 0.100, p < 0.001) with all predictors significant, except weekly minutes of moderate PA and participant HRFK (p < 0.05). The aHRFK model was also significant (F = 45.736, R[superscript 2] = 0.108, p < 0.022) with all predictors significant except weekly minutes of moderate PA, education level, and participant HRFK (p < 0.05). Conclusion: U.S. physical educators possess high levels of HRFK, however HRFK is not a significant predictor of their teaching and assessing HRFK. Weekly vigorous PA, was the strongest predictor, suggesting that teachers' commitment to their own personal PA is critical to teaching and assessing HRFK among their students. Further research should consider vigorous PA along with other potentially related variables to more fully describe and predict physical educators' teaching and assessment of HRFK.