It is understood the man was fishing off rocks west of Ballyheigue in the Kerry Head area when he was swept into the water on Friday afternoon.
The Irish navy vessel LÃ‰ Orla, Glenderry and Ballybunion Coastguard units and Fenit RNLI lifeboat are involved in the search.
The Shannon based rescue helicopter is also in attendance.
There are reportedly difficult sea conditions around the cove area where the missing man was last seen.
A search operation has resumed for a man missing off the County Kerry coast in the Republic of Ireland.