Pennell is regarded as one of the brightest young players on the books at Warriors after bursting into the first team this season.
The 20-year-old, Worcester born and bred, has been praised by Director of Rugby Mike Ruddock for his commitment and determination to battle back from injury in recent seasons to continue his development.
He was rewarded with his Guinness Premiership debut on the opening day of this season and the England Under-18 international has made five competitive first team starts this season, including two in the top-flight.
Young fly half Joe Carlisle has already given Warriors supporters a taste of what is to come after a thrilling first team debut in the pre-season clash with London Irish, including a stunning individual try.
The 20-year-old impressed in the Guinness A League last season after honing his skills in the Academy set-up.
Carlisle was handed a start in the recent EDF Energy Cup clash with London Irish and has featured on several occasions in the European Challenge Cup for Warriors.
Director of Rugby, Mike Ruddock, said: "I'm delighted that two excellent prospects, both products of our Academy system that suit the game we are trying to develop here, have committed to Warriors.
"Chris Pennell has made fantastic progress with his all-round game and whilst there are still things he needs to learn he has already started in the first team on several occasions.
"With the length of contract he has signed, I would expect him to make many more appearances and become a key member of our squad going forward.
"Joe Carlisle is a fine young playmaker who is perfectly suited to the game we want to adopt here.
"He has made significant contributions to first team and Guinness A League games and has a wide range of skills, including being one of the best passers of a ball that we have seen in a long time.
"There are areas of his game that he needs to work on to become first choice, but he is young enough to improve and has the hunger and desire to become a major player with the Warriors over the next three years."