Introduction: Approximately three billion people in Asia, Africa, and the Americas cook with biomass, cleaner cooking technologies with the potential to reduce household air pollution exposure. It is necessary to assess the adoption and long-term use of these stoves, measure perceived benefits among users, and use this information to provide feedback to programs that are implementing new cooking technologies. The aim of this study is to determine the level of adoption and impact of improved biomass cookstoves in the rural area of Lambayeque, Peru, in 2017. Methods: A descriptive cross-sectional study was conducted. A total of 52 homes were surveyed in the districts of Pacora and Íllimo where improved biomass stoves were introduced between 2005 and 2013. A questionnaire for the assessment of adoption and impact indexes proposed by the Global Alliance for Clean Cookstoves was applied. The STROBE checklist was used. Results: The mean number of years with the improved biomass cookstove was 9.1 (standard deviation: 2.9); 51.9% always used the improved stove, and 34.6% never used it due to destruction during the El Niño phenomenon in 2017. The median impact index was 5.62; 19.2% had a very good/good adoption. The median adoption index was 6.5; 25% had a very high/high impact. The use of the traditional or open fire biomass stove persisted in 61.5% of the houses. Conclusion: The adoption and impact of improved biomass cookstoves were acceptable, but traditional stove use persisted in more than half of the houses. Households used a mix of different stove technologies. Gas stoves were used more frequently for breakfast or dinner, while the traditional biomass stoves were used for larger lunchtime meals.