Pupils at Denny High are among 50 schoolchildren being screened for TB.
The youngsters have all been in contact with a child in Forth Valley recently diagnosed with the infectious disease.
However, health officials are stressing the risk of infection is very low.
Screening will also gake place at Wallace High and Raploch Primary School, both in Stirling.
Three separate schools are involved as the child moved from a P7 class to a secondary school. Several teachers are also being offered screening.
Letters have been sent to the parents and guardians of all the children involved.
Dr Jennifer Champion, NHS Forth Valley consultant in public health medicine, said: “There is no need for either pupils or teachers at the schools to be worried as the risk of transmission is very low. However, in keeping with national guidance, we are screening all close contacts, including pupils who have been in the same class as this child.”
TB is caused by bacteria and can be treated successfully with antibiotics.