The incident happened at the Turslliagh wind farm near Tralee, Co Kerry.
Twenty three Danish-manufactured V47 wind turbines stand at the site in Turslliagh. The masts tower over the landscape at a height of over 40 metres, and the blades have a rotary diameter of 47 metres.
For reasons still unknown, a blade in one of the turbines detached and fell to the ground, causing no injuries. The turbine was shut down as a precaution.
The manufacturing company, Vestas, has been notified and an investigation is underway.
This is the second incident involving wind turbines here in Ireland in as many weeks. In Co. Tyrone last week, a full turbine collapsed to the ground. The manufacturer of that particular equipment, German company Nordex, is also investigating.