Watford sacked their second manager of the season on Sunday with Quique Sanchez Flores leaving the club bottom of the Premier League table.
The Spaniard managed just one win in 10 league games in charge during his second spell at Vicarage Road after replacing Javi Gracia in September.
“Quique is a man of great integrity and it was clear how much he wanted to have a positive impact, but ultimately results have dictated our decision,” said Watford chairman and CEO Scott Duxbury.
“The appointment of a new head coach is imminent, and with nearly two-thirds of the season remaining, we will provide all the support necessary to make the coming months successful.”
Defeat to fellow strugglers Southampton on Saturday left Watford six points from safety with just eight points from their opening 14 games of the season.
Sanchez Flores returned to Watford just three months ago having also taken charge for the 2015/16 season when the Hornets finished 13th in the Premier League and reached the semi-finals of the FA Cup.
However, he was unable to recreate that success with his only league victory coming at Norwich last month.
A run of six defeats in 12 games in all competitions also included an 8-0 thrashing at the hands of Manchester City.