Coronavirus test kits and protective equipment are among the medical supplies to be delivered to an island via drone.
Health authorities in Argyll and Bute, where the trial is taking place, said the two-week scheme will enable patients to be diagnosed more quickly.
Urgently needed supplies will be flown between Lorn and Islands District General Hospital in Oban and Mull and Iona Community Hospital in Craignure, Mull, around 12 miles away over the sea.
London-based drone delivery firm Skyports will carry out the trial and operate the flights, cutting delivery times to around 15 minutes.
Currently, the supplies are mainly delivered via road and a 45-minute ferry crossing.
Those behind the scheme hope it will enable drone deliveries to be set up for other health boards across the UK.
They said it marks a milestone for drone flights in the UK as the medical deliveries will be going out of sight of the operator.
The project is a collaboration between Skyports and Thales.
Joanna Macdonald, Argyll and Bute Health and Social Care Partnership chief officer, said: “I am delighted that Argyll and Bute Health and Social Care Partnership is again at the forefront in Scotland using new technologies to benefit our patients.
“The use of drones provides real opportunities to improve services and will help enable quicker diagnosis for our patients.”
Duncan Walker, Skyports chief executive officer, said: “Delivery drones are a fast and reliable solution for vital medical supplies.”
He added: “Skyports is proud to assist the NHS in Scotland with their Covid-19 response, helping to provide the essential healthcare that people need in harder-to-reach areas.
“Our trial in Argyll and Bute provides an important short-term response to the current pandemic and lays the foundations from which to grow a permanent drone delivery operation across a network of healthcare facilities around the country.”
The trial is due to run until June 5.
Alex Cresswell, chief executive of Thales UK, said: “This trial demonstrates the positive role that unmanned technology can play in our society and represents a landmark step to accelerate its adoption.”