According to Official Guinness Records,
The largest Pickleball tournament consisted of 370 players and was organised by the Tennis Competitors of Dallas (USA) at FieldhouseUSA in Frisco, Texas, USA, on 15 November 2012.
Following a round robin format, the tournament was won by Sandy Cassday and Karen Spika. The record-breaking event was attended by top Pickleball players Bev Yongren, Alex Hamner and Jennifer Loncore.
For a complete list of 2012 records, please visit 2012 Guinness Records in United States.