Kamala Police were notified by the 191 emergency radio centre at about 12:05pm that a person had jumped from the True network signal tower near Phuket FantaSea in Moo 5, Kamala.
Officers arriving at the scene found the man suffering from back injuries. Police said he was incoherent and unable to provide any identifying information.
Rescue workers from the Kamala rescue unit provided first aid before transporting him to Patong Hospital for treatment.
A local resident, identified by police as Orasa Phongphiew, told officers she had been driving out of a nearby alley when she saw the man walking towards the area while talking to himself.
She said she then heard him shouting that he wanted to die. A short time later, she learned that someone had fallen from the signal tower and called the 191 emergency hotline to report the incident.
Police said no identification documents were found on the injured man.
His identity remains unknown and officers are continuing their investigation while awaiting further information from Patong Hospital.
If you or anyone you know is in need of emotional support and counselling, please contact the Samaritans of Thailand at 02-113-6789 (English & Thai) or the Mental Health Hotline at 1323 (Thai).