Background and Purpose. The standing single-leg (SSL) heel-rise test is a measure of plantarflexor strength and endurance. However, reference values have yet to be determined for children. The purposes of this study were to: (1) determine the average number, minimum number (cut-off score) of SSL heel-rises for healthy, 7–9 year old children, (2) examine the influence of age, gender, height, weight, and physical activity characteristics upon the number of heel-rises completed, (3) examine interrater reliability, and (4) examine reliability between the number of repetitions counted by observation, and by video-analysis. Method. A total of ninety-five children, aged 7–9, performed SSL heel-rises until fatigue. The number of heel-rises were counted by two examiners and was determined from videotape. Results. The children completed an average of 36 ± 18 SSL heel-rises (COV = 50%). Age, gender, height, weight, or activity level had no significant effect upon heel-rise performance. Excellent interrater reliability (ICC = 0.99), reliability between the motion analysis system and the examiners (ICC = 0.93), was established. Discussion, Conclusion. Therapist visual observation can determine heel-rise count as accurately as when using a motion analysis system. Children who have functional limitations, who perform 13 or fewer heel-rises should repeat the SSL heel-rise test at a later date and/or perform other tests to confirm the plantarflexion muscle strength-endurance impairment prior to initiating an intervention program.