Few studies have investigated the physical demands of golf caddying during high-level golf competitions, yet recent fatalities have raised questions regarding demands relative to physical fitness. PURPOSE: The purpose of this study was to examine the physical demands of a professional golf caddy during a single round of a European Tour Tournament. METHODS: A professional male golf caddy with 27 years of caddying experience (age=47 yrs, HRmax=161 bpm, VO2max=29 ml/kg/min) volunteered for this study. During the first round of 2018 Irish Open, the caddy wore a global positioning system (GPS) device and a heart rate (HR) monitor continuously throughout the round of golf for the recording of displacement and HR responses, respectively. RESULTS: The total time (TT) of the round was 226 min with 53.5% walking and 46.5% standing, and the total distance covered by the caddy was 8.63 km, with mean and peak traveling speeds by of 2.3 km/h and 9.7 km/h respectively. The mean HR was 110 bpm (68.3% HRmax), with a peak of 136 bpm (84.5% HRmax). The caddy spent most (62.3%) of the TT at moderate intensity (64-<77% HRmax; ACSM’s guidelines, 2013), 27.5% of the TT at light intensity (50-<64% HRmax), and only 10.2% of the TT at high intensity (77-<94% HRmax). In general, uphill movements elicited a higher HR response. CONCLUSIONS: These results suggest that cardiovascular demands of golf caddying were primarily moderate intensity activity during the round of elite golf. However, high intensity activity was also observed when the caddy climbed hills continuously. These findings may provide useful information for justifying the need for aerobic training programs for a professional golf caddy, relative to a low current cardiovascular fitness level.