The ladies toilets at Preston Bus Station will be closed for refurbishment from Monday, July 17.
The work is part of the major redevelopment of the bus station and will include a wide range of work including essential maintenance of the building, replacing the electrical system and pipes, as well as renovating the toilet facilities.
During this work, which is expected to take until October, alternative toilets will be available initially opposite stand 137, towards the north end of the bus station.
Plans are currently being looked into for additional temporary toilets during this time.
Lancashire County Council, which owns the bus station, says this work does not affect the men's toilets.
Linzi King, manager of the bus station, said: "This work is part of the overall redevelopment of the bus station and includes renovations on the building itself, which is why this will take some time.
"Alternative toilets will be made available for the public, but unfortunately this initial temporary arrangement may not be suitable for everyone, as these toilets are accessed using stairs. Alternative public toilet facilities can be found at the indoor market.
"We're sorry for any inconvenience that this may cause while this important work is carried out."
For help to find or access the toilets, ask a member of bus station staff or call the Security Office on 01772 556 031.