In recent years, indoor air quality (IAQ) became a primary issue that needs more and more focus because of the increasing number of exposed population. The paper reports the current state of the art of several European countries about indoor air quality, focusing on the initiatives performed in Italy to respond to WHO recommendations. Even EU underlines the priority of energy efficiency strategies, at the same time recommends to reach healthier indoor environments and to develop a specific European strategy on IAQ. Currently, several European Union (EU) countries have introduced in their legislation the rules related to IAQ; in Italy, there is not any reference-specific rule around these topics. The paper analyses the scientific literature, the WHO guidelines and also the ISO, CEN and UNI suggestions, norms and guidelines by other European countries and/or other standard values, such as limit or reference values regarding outdoor air, for better understanding the current framework. Since many years, problems from exposure to indoor air pollutants have been a matter of concern for national as well as EU legislators, and an increasing number of states have been addressing the need for policies regarding health and strategy through specific studies. The EU has often addressed the importance to measure and assess IAQ, the relative impact on health and possible recommendation regarding future measures.