The impact that bilingualism has on cognition is a topic that has increasingly been researched and studied. The aim of this paper is to provide an overview of the knowledge obtained from various research in the past, as well as an overview of the knowledge of the latest researches so that the overall results can be implemented in practice. For the purpose of this paper 514 research papers were found and with the application of the PRISMA protocol based on exclusion criteria and inclusion criteria, selected for this study which included 111 papers, i.e. 154 along with the original literature. The results have shown that, when it comes to the executive functions, memory, attention, language processing and dementia, or cognitive decline that appears in the aging process in general, there are divided opinions. The research on the topic of Down syndrome, developmental language disorders and autism spectrum disorder indicates the absence of additional language difficulties caused by bilingualism. In fact, a positive influence of bilingualism has been observed in children with autism spectrum disorder. Bilingualism advantage has also been proven in the field of theory mind and aphasia. Therefore, the majority of papers used for this paper indicate a positive influence of bilingualism on cognition, and note no harmful impact or influence of bilingualism, even in the case of people suffering from developmental disorders for which it was/is considered that they are not capable of learning/acquiring a second language and that it may cause them additional difficulties. It is necessary that the results presented, both those that advocate the benefits of bilingualism, as well as those who oppose it, are studied with a dose of criticism. Lastly, it is necessary to consider all the obtained evidence and apply in the professional practice, as every child has the right to develop their own linguistic identity and culture.