Surrey Police were called to an address in Bletchingley Road, Godstone, near Reigate, just before 11am on Monday.
The victim has not yet been formally identified and a post mortem to establish the cause of his death is due to take place.
Officers have been making house-to-house enquiries, and one lane of the A25 was closed while searches were carried out.
Detective Chief Inspector Colin Pirie said: “The investigation is still in the early stages but we would like to reassure the local community that we are doing everything we can to establish the circumstances of this man’s death.
“Our thoughts remain with his family and friends at this time who are being supported by specialist officers.
“If you have any information which could help us, please get in touch with us as soon as possible.”
Anyone with information can contact Surrey Police on 101, quoting reference PR/P20095551, or call Crimestoppers anonymously on 0800 555 111.