The doctors were travelling on the Stena Lynx service from Fishguard
When a ferry captain asked if there was a doctor on board after a passenger was taken ill, he was not expecting 18 to come forward.
But that is what happened on Stena Line's Fishguard to Rosslare service.
Seventeen medics were on their way to Wexford for a golfing holiday while another was travelling independently.
Ferry company spokesman Eamonn Hewitt said: "This man was certainly very well attended, having 18 doctors taking good care of him in his time of need."
The call to a man suffering an angina attack took place onboard the Stena Lynx last week.
Mr Hewitt said "Following an announcement by the captain over the tannoy, a group of 17 doctors, travelling with Stena Line on their way to a golfing holiday in Wexford, answered the call for help.
"This was supplemented further by an additional doctor from Wexford who was also onboard at this time.
"Whilst our staff are trained in first aid procedures, this man was certainly very well attended, having 18 doctors taking good care of him in his time of need.
"The staff phoned ahead and when the ferry arrived in Rosslare there was an ambulance waiting and transported the man to Wexford General Hospital."