The 62-year-old was walking in Roslin Glen, Midlothian, when he fell through a manhole and plunged seven feet into the sewer below.
Fire, police and ambulance crews were called to the scene and found the victim conscious but covered in waste.
He had to be “decontaminated” before being taken to the Edinburgh Royal Infirmary.
A spokeswoman from the ambulance service said: “A man fell seven feet into a manhole. The man landed on his back and sustained back injuries which are not life-threatening.
“Crew used a stretcher to rescue the man but because of the nature of the hole, it took some time to successfully remove him.”
She added: “He was covered in sewage. We gave him a wash down before he was taken away in an ambulance.”
A fire service spokeswoman said: “We rescued a male who had fallen two metres into what our teams have called a concrete plinth.”