This study is dedicated to the evaluation of the water surface dynamics of the largest and most important natural lakes in the Republic of Moldova: Manta and Beleu. The lakes' area represents the main natural ecosystem of the country and is a shelter to thousands of animals and plant species which are included in a protected area network. The lakes are situated in the lower Prut floodplain, with main water sources being the river Prut through channels and during floods, as well as groundwater and precipitation. The regulation of the river Prut, climate change and the increasing frequency of droughts and floods have a certain impact on water surface dynamics. The main methods used to evaluate the lakes' extension dynamics are the analysis of satellite images and the application of the NDVI and its variations. The main satellite images used in this study are Landsats, that were identified from 1975 to the present. Thus, the estimation of water surfaces was performed for different decades, and the tendencies were also identified. The increasing magnitude of drought and floods in the last decade influenced the lakes' extension the most. The most recent catastrophic drought in 2022 decreased the surface of Beleu by up to 4 km2 and that of Manta by up to 7,5 km2, while the most recent floods in 2020 flooded up to 30,2 km2 of the area of Beleu and up to 30,4 km2 of that of Manta. The average water surface in recent years is 6,2 km2 for Beleu and 13,4 km2 for Manta.