Interior ministry forces recaptured the Ibn Sina Teaching Hospital along with other medical facilities including a blood bank and a clinic, Staff Lieutenant General Abdulamir Yarallah said in a statement on Saturday.
Lieutenant General Raed Shakir Jawdat, the commander of the country's federal police, said the area where the hospital is located, Al-Shifaa, had been completely retaken, limiting ISIS's presence in Mosul to the Old City.
"Our forces are advancing from three sides and are pursuing the terrorist groups in the few remaining areas of the Old City," Jawdat said in a statement.
Iraqi forces have been fighting to retake the Old City for weeks, and launched a renewed assault on the area on June 18.
But ISIS made sure that the Nuri mosque was not captured intact, blowing it up along with its famed leaning minaret as Iraqi forces closed in.
ISIS overran large areas north and west of Baghdad in 2014, but Iraqi forces backed by US-led air strikes have since regained much of the territory they lost.