The 78-year-old was suffering from a urinary infection and being treated with antibiotics, his friend and spokesman Pepito Fornos, who was with Pele at the hospital, said.
"Everything is under control. Everything's fine."
Pele was admitted late on Tuesday as a precaution after attending an event in the French capital with France's World Cup winning youngster Kylian Mbappe.
He was still in hospital on Wednesday evening, though in a possible sign he was making a recovery, he said on Twitter: "I met Kylian Mbappe and his parents last night in Paris at @Hublot event. We talked goals, World Cups and watches. Great company!"
Earlier, Mbappe had written on social media: "I had the chance this evening to spend a once-in-a-lifetime moment with the living legend @Pele."
Pele, revered by many as football's greatest player ever, is alone in winning the World Cup three times, first lifting the trophy aged 17. The Brazilian was swift to praise Mbappe after he set last year's World Cup in Russia alight with his electric speed and goalscoring.
Mbappe became the youngest player (19) to score two goals in a World Cup game since Pele in 1958. He also became the first teenager since Pele to score in a World Cup final.
"If Kylian keeps equalling my records like this I may have to dust my boots off again," Pele tweeted at the time.
Mbappe replied: "The King will always remain King."
The Paris St Germain forward told Tuesday's event he would never match the Brazil great's scoring tally during his career. Pele says he has scored 1,025 goals.
"Even with the goals in playgrounds, goals on the PlayStation, I could never equal (that)," the 20-year-old said at the sponsors' event.
Mbappe and Pele had been scheduled to meet late last year but had to postpone, again because of Pele's health, French media said.
(Reporting by Sudip Kar-Gupta in Paris; additional reporting by Andrew Downie; Writing by Richard Lough; Editing by Christian Radnedge and Toby Davis)
