First trip to Vicarage Road in nine years
Gillingham's reward for beating Southend United in the opening round of this season's EFL Cup is a trip to Premier League side Watford.
The draw was made live on Sky Sports on Wednesday night, and Justin Edinburgh's team were paired against Walter Mazzarri's side.
Watford won the last meeting between the two sides, which also came in the League Cup, 3-0 in August 2007 at Vicarage Road. The Gills' last victory in Hertfordshire came in March 2003's Division One fixture, as Paul Shaw scored in a 1-0 win.
The tie will take place on August 23, 7.45pm kick-off; ticket information will follow in due course.