The school made an announcement on Wednesday that the 6-foot-7 sophomore, who averaged 5.9 points and 4.5 rebounds per game last season, will not put his name in for the June 26 NBA draft.
"Playing in the NBA has always been a dream of mine, but I want to make sure that I'm NBA-ready before I make that jump," Poythress said. "By coming back, I'll be so much closer to earning my degree in business and it will give me another year to prepare my game and my body for the next level."
According to several league executives, Poythress was considered a second-round pick.
It will be interesting to see Poythress' role next season in what could be a crowded Kentucky frontcourt.
Freshman big man Dakari Johnson also announced Wednesday he will return next season. Guards Aaron and Andrew Harrison are still waiting to make decisions before Sunday's deadline. Julius Randle and James Young are among those who already declared for the NBA draft.
"This year has been for me a year of transition, growth and so much fun! I've learned a lot about myself personally through adversity and triumph which I know made me a stronger individual," said Johnson, who averaged 5.2 points and 3.9 rebounds. "I would like to thank my brothers (teammates) for pulling together and stepping up and taking the road that many don't travel. What memories! I would like to thank Coach Cal and the staff for trusting and providing me the opportunity to grow and build on my skills."