Paramedics used forceps to grab hold the fish's tail they could see down the man's throat.
They tried five times to pull the fish free but its barb and gills were stuck in the angler's throat.
They finally yanked it free on the sixth go but by that time the man had stopped breathing for three minutes.
He was revived in the ambulance and after being treated and checked over in hospital was allowed home having made a full recovery.
Paramedic Matt Harrison said the man's friends explained he had been joking around with the catch and put it over his mouth.
Harrison said that at that moment the fish wiggled free, promptly jumping straight down the patient's throat.
"We needed to get the fish out or this patient was not going to survive the short journey to Royal Bournemouth Hospital.
"I used a laryngoscope to fully extend the mouth and throat and saw what appeared like an altered colour of tissue in his throat.
"Using forceps I was able to eventually dislodge the tip of the tail and very carefully, so as not to break the tail off, I tried to remove it - although the fish's barbs and gills were getting stuck on the way back up.
"I was acutely aware that I only had one attempt at getting this right as if I lost grip or a piece broke off and it slid further out of sight then there was nothing more that we could have done to retrieve the obstruction.
"Eventually after six attempts the fish came out in one piece and to our amazement it was a whole Dover sole, measuring about 14cm in length."
He added: "I have never attended a more bizarre incident and don't think I ever will.
"We are all so glad the patient has no lasting effects from his cardiac arrest, which could so easily have had such a tragic and devastating outcome."
Martyn Box, the operations officer who also helped the dying man said: "The boy's [friends] were giving good CPR on our arrival as instructed by the control room staff.
"Initially we didn't know what the patient was choking on, but as we questioned them further we were told he had a whole fish stuck in his windpipe."
Box added: "This story just highlights how important it is for friends or bystanders to step in and start CPR when someone's heart has stopped."