Unvented biomass cookstoves present a recognized respiratory health risk in developing countries. The purpose of this study was to characterize fine particle indoor air pollution (IAP) concentrations in dwellings using traditional cookstoves in a rural community in India. It also aimed to understand if a culturally acceptable clean cookstove intervention was needed to reduce the risk of respiratory illnesses from exposure to combustion products from traditional cookstoves. We took PM2.5 concentrations and ≤0.5 µm particle counts inside a sample of dwellings during the use of traditional cookstoves. The data were analyzed to indicate the magnitude of IAP. In households with traditional cookstoves, average PM2.5 concentrations were 172.8 µg/m3, and the particle counts ≤0.5 µm averaged 346,150. The PM2.5 concentrations from the traditional cookstoves were shown as unhealthy per the PM2.5 air quality index (AQI) of the U.S. Environmental Protection Agency. Partnering with local community members, an improved prototype metal cookstove was designed to be fuel-efficient and vent the smoke out of the dwellings. We found PM2.5 concentrations and ≤0.5 µm particle counts for the new stove averaged 21.5 µg/m3 and 60,812, respectively. The PM2.5 concentrations from the new stove are at an acceptable level per the AQI.