<p>Hospitals are supposed to be places of healing, but poor indoor air quality (IAQ) can actually increase the risk of respiratory infections for both patients, care givers and staff. The objective of the study was to develop a respiratory risk index to ensure healthy IAQ of patients and health care workers fora city hospital. To fulfil this indoor air quality such as PM10, PM2.5, SO_x, NO_x, microbial load, relative humidity, air velocity and temperature were measured seasonally in three ward of cardiac unit where patient get admitted to implant pacemaker. Physiological data such as tidal volume and respiratory rate was also taken from the hospital records. Participants who are being admitted to the hospital for the first time and undergoing their first pacemaker implantation are included in this study and subjects with a known respiratory disease are excluded from this study. Using these data respiratory deposition dose (RDD), was measured separately for male and female patient, which was used to develop a linear equation of Potential Respiratory Risk Index (PRRI). The study found that PM10 and PM2.5 concentrations were highest in summer (65.23 and 42.82&#xa0;μg/m³), with a bioaerosol load of 1254&#xa0;CFU/m³ during rainy season. All data exceeded the World Health Organization's recommended standards. The PRRI can predict the risk of indoor air pollution for hospitalised patients over a specific time period. These findings can be applied to hospital management in developing countries located in tropical areas.</p>