The history of autism spectrum disorder (ASD), although relatively short, is the subject of numerous studies. Many of the issues arising from the research and work with children with ASD are answered, but the question of cause still intrigues many experts in the field of ASD. During the last decade the focus of many studies was placed on genetic causes of autism spectrum disorders. Although genetics is very important in defining and understanding the etiology of ASD, it is not possible to provide a comprehensive explanation of the disorder on the basis of genetic research. The focus of research is therefore shifted to environmental causes. Environmental factors play an important role but they are often wrongly interpretated. Especially during the process of dealing with the fact that their child has a diagnosis of ASD, parents search for causes and often accept and advocate for theories that are not necessarily supported by the results of scientific research. Given that unfounded causes of ASD are often present in the media today, the whole view of environmental causes and related research is viewed through the prism of skepticism. The term "environmental causes" refers to any factor which may affect the development of ASD, but that does not include genetic factors. The aim of this paper is to provide a structured overview of current studies and highlight the possible role and importance of various environmental factors in the occurrence of autism spectrum disorders. Identifying environmental factors that affect the risk of ASD has great potential to open the way to changes in the perception of and accession to the disorder. The environment is a factor that can be altered and that consequently provides a significant improvement in the prevention of ASD. Many theories and environmental factors that by current research have an important role in autism spectrum disorders are highlighted, as also the mechanism of the influence of these factors. Finally, a critical review of the theories of environmental factors that explain autism spectrum disorders is provided.