It is a slightly harsh decision given that last season Mel, who had previously led Betis to promotion from the second division (Liga Adelante), helped them qualify for the Europa League and has this term taken them into the knockout phase of the competition, reports Xinhua.
However, Betis have struggled for form this time around after losing key players such as Benat Etxebarria and Jose Canas and are currently two points adrift at the bottom of the table.
Sunday saw Mel's former club twice take the lead in their home game against second from bottom Rayo Vallecano, only to be twice pegged back with the equalising goal coming in injury time in a match Betis deserved to win.
Although Betis worked hard and were unlucky not to take all three points from the game, it is also true that they looked fragile and struggled to pick up pace after Alvaro Bueno had equalised for the first time early in the second half.
Mel, who had previously coached Rayo, had been at Betis for three years and it is also no secret that his relationship with the club directors had become increasingly strained after the summer saw the loss of important players with only free transfers and loan signings to replace them.
Although Mel's successor is yet to be confirmed, it appears that former Villarreal and Bruges coach Juan Carlos Garrido will be named as his replacement.
Mel is the second coach to be sacked in the La Liga this season after Osasuna's Jose Luis Mendilibar was shown the door after just three games in the campaign.