The anime series started airing on TV Tokyo in 2004 and ended in 2011. The anime is produced by Sunrise, and has been aired on Animax, TV Tokyo, and TXN. Seven seasons have been created during its seven-year run. Unlike the manga which is aimed at older audiences, the anime adaptation has been toned down to a level suitable for family audiences. ADV had previously announced they had acquired exclusive rights to an English dub of Sgt. Frog(for $408,000). However, on July 4, 2008, it was announced that rights to the English release were transferred to Funimation Entertainment.
The anime ran almost year-round, which each season beginning in the first week of April and ending on the last week of March. The first season aired on Saturdays, but the show was moved to Fridays for the second and third seasons. The show returned to Saturdays for seasons four, five and six, and the final season aired on Sundays.
ADV Films had originally added a brief teaser page to their website, announcing their licensing of the anime. The site turned to static before playing a short clip of Keroro dancing to "Afro Gunso," then leaving the message "hacked by the frog." This was followed by a press release from ADV on November 20, 2006, stating that they had licensed all Sgt. Frog properties (except the manga, which was already licensed by Tokyopop) for the US. It was once confirmed that the anime dub would be released on DVD in the United States in February 2007. However, ADV Films had never confirmed a release date. ADV announced at Comic-Con International 2007 that the US release date had been delayed because of TV negotiations but would not comment on which networks they were talking to. In a DVD included with the December issue of Newtype USA was an English-language trailer for Sgt. Frog released by ADV, with voices for Keroro (said to be voiced by Vic Mignogna), Natsumi, Fuyuki, Aki, and the narrator. ADV was 90% done on getting a deal with the show, though they created a separate team to work specifically on it that included people from Summit Entertainment (the company that worked with 4Kids Entertainment during the time they had Pokémon). They had dubbed three episodes, but they were dubbed three times because ADV created three different pilot-packages for television to see which one worked the best. They made an otaku/fan pilot, a mass-market pilot, and a kids' pilot. They received positive responses from three different networks. Cartoon Network liked the mass-market pilot, while Nickelodeon liked the kids' pilot. Nickelodeon told them that they would air the show if ADV got the merchandising rights. However, as of July 4, 2008, the English license for the first 51 episodes of the Sgt. Frog anime was transferred to Funimation Entertainment through a deal with Sojitz.