It is a pleasure to introduce to you this scientific book under the title Physical Activity and Health Aspects of COVID-19 Pandemic. In January 2020, the World Health Organization (WHO) declared a new COVID-19 outbreak to be a public health emergency of international concern. Since then, there have been many confirmed infections and many human deaths. A highly effective method for slowing the spread and infection of the virus is self-isolation or quarantine. However, some countries have adopted measures like travel restrictions and school closures. These extraordinary arrangements have had negative physical and psychological impacts, with increased physical inactivity and sedentary behaviour. Before the pandemic, in “normal” conditions, analyses showed that more than 3.2 million people in the world die annually directly due to physical inactivity, while some analyses speak of as many as 5 million. When we talk about the leading factors causing mortality and disease development, according to the World Health Organization, physical inactivity is in the high fourth place and is significantly related to other factors and equally represented as a cause of mortality regardless of the level of development of a country. During the pandemic, other diseases and health risks did not disappear, although the focus of many systems was on the prevention and treatment of patients suffering from COVID-19 virus. A large number of experts in the field of health, kinesiology and other sciences point out the importance of preserving prevention programs in all other segments, regardless of the new pandemic. Physical activity is an indispensable segment of the prevention of many chronic non-communicable diseases, some of which are the leading mortality factors in the world. The consequences of increased physical inactivity, even if due to a pandemic, will be felt by millions of people of all generations. The negative curve of many countries has been present for decades and there is an objective fear that it could worsen significantly during the pandemic period. Mankind will feel the consequences for many years to come in many segments and it is important to point out the importance of physical activity in all the forms available to us. The topic of this scientific book is related to the COVID-19 disease that is considered the worst pandemic in modern times. It covers some aspects of the pandemic, and the reader can find three very interesting chapters that cover important topics as the influence of COVID-19 pandemic on physical education and psychological health, as well as the influence of COVID-19 pandemic on overall well-being. The authors of the book chapters come from a large number of countries, and they certainly are well-respected and experienced researchers. We firmly believe that this scientific book will be a valuable assistance to a variety of scientists, practitioners and, of course, students to better understand the events and problems that arose during the pandemic and to help solve them.