The unique landmark was celebrated recently with a presentation to the trio.
Lynne Connell, Anne Anderson and Linda Booth all joined the old Tesco store in Falkirk in the same week in 1981.
They subsequently moved to the store at Redding.
Lynne, from Stenhousemuir, is the cash office assistant.
Anne, from Falkirk is a customer assistant on fresh foods, and Linda, also from Falkirk, is a customer assistant on grocery.
The retailer paid tribute to the long-serving staff members.
A spokesman said: “To have one colleague reach 40 years service is amazing in itself, but to have three colleagues all marking this milestone is something else.
“We are very proud of them. They are such an important part of the team.
“Unfortunately due to current restrictions we haven't been able to celebrate as we would have liked to but will hopefully one day soon.”