Adams, 50, has been handed the reins at Los Carmenes until the end of the season after Lucas Alcaraz saw his third spell as Granada boss end following a 3-1 loss to Valencia.
Five losses in six games leaves the club in 19th place and seven points from safety with only seven games remaining.
Adams is vice-president of DDMC - a football club management company owned by Granada president John Jiang - and has been working with the Spanish outfit since November.
But now the former Wycombe, Portsmouth and Gabala boss is stepping in to the manager's seat as he looks to pull off a "miracle."
"I've been here five months and I didn't see this coming," Adams said at his unveiling.
"I want to thank Lucas Alcaraz and I wish him all the best. I will try to win every game and will try some things in training to liven up the team as we try to achieve a miracle."
Adams suggested he does not see the position as a long-term role but said he is ready to ruffle a few feathers among the playing staff to reach his goal.
Read the full article on eurosport.co.uk: Tony Adams ready to shake things up at Granada