Krustrup, P and Mohr, M. Physical demands in competitive ultimate Frisbee. J Strength Cond Res 29(12): 3386–3391, 2015—The objective was to study game demands in competitive ultimate Frisbee by performing match analysis during a game. Thirteen moderately trained (Yo-Yo intermittent recovery test levels 1 and 2 [Yo-Yo IR1 and IR2] performance: 1790 ± 382 m and 657 ± 225 m, respectively) competitive male ultimate Frisbee athletes played a game in which activity profile using Global Positioning System (GPS) technology and heart rate (HR) were recorded. Game HRmean and HRpeak were 82 ± 2% and 99 ± 1% of maximum heart rate, respectively. Total game distance was 4.70 ± 0.47 km, of which 0.63 ± 0.14 km was high-intensity running and 0.21 ± 0.11 km was sprinting. In the second half, 10% less (p ≤ 0.05) ground was covered with high-intensity running compared with the first half (0.28 ± 0.08 km vs. 0.31 ± 0.07 km). Less (43–47%; p ≤ 0.05) high-intensity running was performed in the third 9-minute period of each half compared with the first two 9-minute periods of the same half. Players performed 17.4 ± 5.7 sprints during the match. Yo-Yo IR2 performance correlated to the amount of high-intensity running in the last 9 minutes of both halves (r = 0.69, p ≤ 0.05), whereas Yo-Yo IR1 performance correlated with total sprint distance (r = 0.74, p ≤ 0.05). Ultimate Frisbee is an intense intermittent team sport with high cardiovascular loading and clear indications of fatigue toward the end of each half. Yo-Yo IR test performances correlate with physical match performance.