The Macdonald Inchyra hotel in Grangemouth, Falkirk, was evacuated on Sunday evening over concerns of a "strong smell of chlorine" coming from the swimming pool.
A spokesperson for Macdonald Hotels said: "Following reports of a stronger than normal smell of chlorine from the swimming pool at the Inchyra hotel in Grangemouth, guests were initially evacuated to the car park, then accommodated in another wing of the hotel as a precaution while the fire brigade carried out investigations into the cause. We are pleased to report that, following checks, guests were allowed back into the hotel and normal service was resumed."
Eleven people were in the care of the Scottish Ambulance Service, and crews have now left the scene.
A Scottish Fire and Rescue Service spokesperson said: "We were called at 7.30pm on Sunday, 26 September to assist partners following reports of a strong smell of chlorine at a hotel on Grange Road, Grangemouth.
"Operations Control mobilised two appliances and specialist resources to the scene, where crews assisted partners by making the area safe."