The unnamed man was working at the `Black Swan` star`s home when he started choking, coughing up blood and vomiting and then collapsed and Mila had her friend call the emergency services while she put the worker in the recovery position.
According to gossip website TMZ, level headed Mila, 28, grabbed the man`s head and turned it to the side so he wouldn`t choke, while another person stuffed a wallet in his mouth so he wouldn`t swallow his tongue.
The kind-hearted actress also offered to travel to the hospital in the ambulance with the man but was told it wasn`t necessary.
He has since made a full recovery.
Mila`s heroics came just a day after her stalker Stuart Dunn was arrested after violating a stay away order when he allegedly arrived at her gym for the third day in a row.
Security at the establishment are said to have sounded the alarm when the man - who is also reportedly homeless - was recognised loitering at the front of the building.
He was arrested back in January for breaking into her home, although he pled no contest to the unauthorised entry onto her property and was put on probation for three years.
He is now thought to be under evaluation in a mental facility and could be imprisoned as a result of his actions.