The four casualties were all female and were taken to Forth Valley Royal Hospital by ambulance following the blaze at Sir John Graham Court.
Six other residents at the complex, which contains 19 flats and bungalows, were also treated for smoke inhalation.
More than 35 firefighters attended the incident, with additional crews from Denny, Falkirk and Bo\’ness also there.
The blaze resulted in one property being destroyed, while eight other residential units suffered smoke damage.
In a statement, the Scottish Fire and Rescue Service said that when they first arrived at the scene, there was an unknown number of people still unaccounted for in the building.
Firefighters wearing breathing apparatus and using high pressure firefighting hose reels and a hose line were eventually able to extinguish the fire and search the property.
The statement said: \”Two people have been rescued this evening by firefighters and were taken to Forth Valley Royal Hospital along with another two casualties, following a serious flat fire at Sir John Graham Court in Larbert.
\”At 20:36 hours Scottish Fire and Rescue Service Maddiston Control received a 999 call to a fire alarm ringing at Sir John Graham Court, Larbert.
\”Fire crews from Larbert and Denny fire stations were initially sent to the scene and arrived to find a well-developed fire within a ground floor flat and an unknown number of people still unaccounted for within the building.\”
An investigation into the cause of the blaze has begun.
An SFRS spokesperson added: \”Any fire in someone\’s home must always bring home the importance of working together to prevent fires and raise awareness of how to be safer from the risk of fire in the home.
\”At this time of the year we ask people to pay particular attention to the use of candles in the home, which must never be left unattended.\”