The current research is the first study of standby energy consumption in households in Ukraine. It provides insights to the scope of the problem and the opportunities to improve the situation. Standby power refers to power consumed by appliances when they are not performing their primary function and are switched "off". Measurements of 50 households were performed. Standby power was measured and a questionnaire was used to find out the behavioural patterns. The combined standby power use is about 23.4 W per household, resulting in national 1.3 TW h per year and 0.8% of the national electricity consumption respectively. The CO2 emissions from standby account for 0.1% of the emissions in Ukraine per year. Different scenarios show the possibilities to reduce standby consumption and CO2 emissions from 10% to 70% under different conditions. The main determinant of household electricity consumption is the number of appliances it has. Levels of standby power use are lower in Ukraine than in developed countries. However, the tendencies are such that the penetration level is growing, and, particularly, of new appliances with standby modes. It is pointed out that there is a need for national standards enforcement, raise of public awareness and price incentives for the reduction of standby power consumption.