In the present study an attempt has been made to develop a protocol for IAQ monitoring in naturally ventilated buildings. The detailed description on each step in the protocol will provide the researchers and practitioners to identify the IAQ parameters for monitoring, number of samples to be collected, identification of sampling location, instrumentation required, and QA/QC policies that need to be considered in the IAQ studies. Further, the protocol has been evaluated for IAQ assessment in a naturally ventilated school building located close to an urban road at Chennai, India.