The Health and Demographic Surveillance System (HDSS) is a periodic follow-up survey platform that monitors population changes in areas that lack reliable civil registration systems. Based on the data from the HDSS program, started in two areas in Lao PDR in 2010, this paper examines the dynamics of a remote rural population (Xepon) in comparison with that of the population in an agriculturally developing area (Lahanam). According to our analysis, high fertility and high child mortality rates were the main features of the population of Xepon : the total fertility rate (TFR) was 4.5 ; the infant and under-5 mortality rates remained as high as 69.8 and 95.6, respectively, per 1000 live births ; and the average life expectancy was 62.1 years. In contrast, data from Lahanam reflected a demographic transition, with an average life expectancy of 63.9 years and a TFR of 1.3. If the TFR follows the trend found in Lahanam, which is associated with the increased use of contraceptives, it is projected that the population of Xepon will decrease and age within 50 years. This kind of demographic transition is to be expected in the not so distant future.