Studies on the implications of population density on energy consumption in small and medium-sized cities in low- and middle-income countries are limited. This paper estimates and analyses energy consumption, using a diverse set of methods, to compare two medium-sized cities in Thailand with similar urban forms and socioeconomic characteristics but different population densities - namely, the less dense city Chaiyaphum and denser city Roi Et. The results reveal that the annual household electricity consumption per capita of these two cities is similar, showing no implications of density. However, private transport energy consumption per capita in Chaiyaphum is 22 per cent higher, supporting the hypothesis that a less dense city will have higher transport energy consumption. The key factor identified is the greater distance travelled by households located in the peri-urban areas in the less dense city. This has important policy implications for urban planning and urban development practices in Thailand.