Which episode had 30.6 million viewers listed?

The episode listed with 30.6 million viewers was “Just Say Yo.”

“Just Say Yo” is the 19th episode of season 3 and aired on February 15, 1993. The episode follows Will and Carlton after they take amphetamines that Carlton obtained to help him study. The story turns the resulting crisis into a cautionary comedy about peer pressure, medication, and the dangers of treating stimulants casually.

The episode’s listed audience of 30.6 million was exceptionally large for the series. It aired during the show’s successful third season, when The Fresh Prince of Bel-Air was firmly established as an NBC hit and Will Smith was becoming a major television star.

The title is a parody of the anti-drug slogan “Just Say No,” associated with the 1980s U.S. drug-prevention campaign. The episode is sometimes confused with nearby season-three entries such as “Robbing the Banks” and “Best Laid Plans,” but the episode table assigns those programs different audience figures: 26.7 million and 27.1 million, respectively.