Bosnia international Dzeko has enjoyed a new lease of life since Pellegrini arrived at the Etihad Stadium and was this week rewarded with a new four-year contract.
Dzeko appeared to fall out of favour under previous manager Roberto Mancini but last season repaid Pellegrini's faith by scoring 26 goals.
Nine of that tally came in City's last 12 games and proved vital to their Barclays Premier League title success but Pellegrini is just as impressed by his developing all-round game.
The Chilean said: "Edin has convinced himself that he can't wait as a striker just to score one goal.
"He has to play for 95 minutes every game, not always scoring but working for the team and making the movements.
"I think he is one of the players who has improved most in his attitude in the game."
Dzeko, a £27million signing from Wolfsburg in 2011, underlined his value with a superb backheeled assist for David Silva's opener in last weekend's 2-0 win at Newcastle.
News of Dzeko's new deal came after Vincent Kompany, David Silva, Sergio Aguero, Samir Nasri and Aleksandar Kolarov agreed fresh contracts earlier in the summer.
Pellegrini said: "I was very pleased because I think that Edin is a very important player for our squad
He is playing very well and so he deserved to renew his contract with the club."
Another striker hoping to catch the eye this term is Stevan Jovetic, whose first season after a £22million move from Fiorentina was marred by injury and illness.
The 24-year-old Montenegro international is now fully fit and, after shining in pre-season, started the season-opener at St James' Park.
With last season's top scorer Aguero still not match-fit and Alvaro Negredo out injured, Jovetic is likely to continue for Monday's visit of Liverpool.
Pellegrini said: "I think Stevan is playing very well
He is in a very good moment with us and I hope he will continue in the same way because he is a very important and very good player for us.
"He is a very good finisher and we will see the real Stevan Jovetic this season."
Source : PA
Source: PA