As part of the large-scale deployment of the WMP Yogyakarta project in late 2021, 13 districts in Dengue Fever (DBD)-hyperendemic Sleman Regency underwent the release of Wolbachia-infected Aedes aegypti mosquitoes. The effectiveness of these mosquitoes in reducing DBD will persist if their population remains at a high percentage. To ensure this, the Sleman Health Office collaborated with the Faculty of Medicine, Public Health, and Nursing at Gadjah Mada University, conducting independent monitoring activities and collecting mosquito samples in 8 districts and at 80 observation points in Sleman from November 30 to December 12, 2023. Preliminary results of the monitoring as of December 15, 2023, indicate that these mosquitoes still maintain a high prevalence, specifically 86.9% in Sleman Regency and consistently over 80% in the 7 districts targeted for releases of Wolbachia-infected Aedes aegypti mosquitoes in 2021. The monitoring results confirm the continued presence of Wolbachia-infected Aedes aegypti mosquitoes in the Sleman area, protecting residents against local transmission of dengue fever infection (DBD).