[Truncated abstract] Cricket is one of the world’s most popular field sports particularly in Commonwealth nations. Despite this popularity there are few published studies on fitness requirements of international cricket. The variable playing duration of three (Twenty20) to 30 hours (five day Test Match) in cricket combined with a large playing field has made it difficult to conduct time-motion studies by traditional means (pen and paper or video recording). Global Positioning System (GPS) athlete monitoring technology now provides a more time efficient and practical method to quantify movement patterns in cricket, provided this technology has adequate validity and reliability. Determination of the validity and reliability of GPS monitoring was required to assess the utility of this approach in quantifying the physical demands of cricket. We compared the validity and reliability of three commercially-available GPS models in estimating cricketspecific movements against criterion measures (400-m athletic track, electronic timing) of distance and velocity. Two models operated with a 5-Hz GPS signal (MinimaxX and SPIPro), whereas the third model operated with a 1-Hz GPS signal (SPI-10). For walking to striding the mean validity and reliability of estimating distances from 600–8800 m by the GPS units ranged from ~0.3 to 5.2% and ~0.2 to 4.0% respectively. In contrast, the mean validity and reliability for estimating sprint distances over 20-40 m including the cricket specific run-of-three, was substantially worse and ranged from ~1.6 to 34% and ~1.6 to 40% respectively. The relatively poor reliability and validity of measuring short sprints with GPS technology means that support staff should interpret small changes and differences in movement patterns with caution. An improvement in GPS hardware specifications, firmware and software is required before GPS data on short sprints can be interpreted with confidence.