Night-time ventilation is a natural cooling technology, in which cold ambient air is used to cool indoor spaces. This literature review analyses how recent studies have defined the effectiveness or efficiency of night-time ventilation. Most studies used the similar indicators related to heat removal, energy saving, cooling demand reduction, and thermal comfort. However, there were significant differences between the definitions of performance of night-time ventilation, both in terms of criteria of judgement and methods of analysis. This review shows that the assessment of night-time ventilation effectiveness or efficiency should be determined according to the task of the ventilation system, such as removal of heat, provide better thermal comfort. The objective of this article is to review the scientific literature on night-time ventilation indicators to identify and categorize the most suitable indicators for performance assessment. The analysis results form a basic framework regarding the application and operation of night-time ventilation.