<P> The Association of Tennis Professionals ( ATP ) does not formally recognize service speed records made in Challenger tour events due to lack of uniformity in these tournaments ' radar guns ( including availability or lack thereof ) . Nevertheless , the serve speed of 263.4 km / h ( 163.7 mph ) recorded by Australian Sam Groth at an ATP Challenger event in Busan , South Korea in May 2012 was measured using approved equipment according to the ATP , and other data gathered appeared within a normal range . However , John Isner holds the ATP 's official record for the fastest serve at 253 km / h ( 157.2 mph ) . </P>
<P> The Association of Tennis Professionals ( ATP ) does not formally recognize service speed records made in Challenger tour events due to lack of uniformity in these tournaments ' radar guns ( including availability or lack thereof ) . Nevertheless , the serve speed of 263.4 km / h ( 163.7 mph ) recorded by Australian Sam Groth at an ATP Challenger event in Busan , South Korea in May 2012 was measured using approved equipment according to the ATP , and other data gathered appeared within a normal range . However , John Isner holds the ATP 's official record for the fastest serve at 253 km / h ( 157.2 mph ) . </P>
who 's got the fastest serve in tennis
who 's got the fastest serve in tennis
Sam Groth
Sam Groth