A 24-year-old soldier serving at the British bases is in critical condition following a fight at a Larnaca bar on Sunday morning, police said.
Another squaddie, 24, has been remanded in custody for five days in connection with the 4.50am incident.
It is believed, police said, that the 23-year-old allegedly attacked the victim hitting him in the face and other parts of his body before striking him on the head with a table. The 24-year-old had his leg in a cast from a previous injury.
The injured soldier was taken to Larnaca hospital and then transferred to Nicosia General where he was put on a respirator.
He has a serious head injury and is currently in a coma.
Oroklini Police Station is investigating the case.
British bases are carrying out their own independent investigation of the incident, according to a spokesman.