Manchester City manager once again labelled Chelsea as 'small team' as he went on to question the style of play Mourinho opted to play with in the second half of the season.
Pellegrini said: "We won exactly the same as Chelsea did this year in a different way last season, absolutely a different way.
"I always try to think in the same way when we are losing or winning. When we play against Chelsea I say the impression is we play against a small team with very good players.
"For me, a big team which has possession of the ball must try to score more goals, must try always to win. But, I repeat, the most important thing is to win. After that you can choose the style you want.
"I don't criticise him (Mourinho). It is different ways of thinking. Every person is different, I don't think every person must be exactly the same.
"Maybe for some managers it's more attractive to score goals. Maybe for another manager it's more attractive not to concede goals. You must ask the fans what they prefer.
"This season I think that Chelsea were the best team, that he (Mourinho) deserves to win the title because he has (had) the most consistent team with very good players.
"I congratulate his owner because he is always improving his squad and I congratulate his fans and Jose Mourinho and the players because they deserve, absolutely, the title."
Mourinho recently criticised Man City's breach of FFP regulations, calling it 'unfair' and asked UEFA to punish with loss of points in the league.
However, Pellegrini was quick to dismiss all those claims in the press conference.
He said: "I don't have a view about that. Every manager can say what he wants about Financial Fair Play rules. We didn't lose points because we don't deserve to.
"There are so many things he (Mourinho) always says that don't matter – a criminal campaign about Chelsea or referees or the FA Cup or other managers or other things."