This specialized work briefly analyses the protection of children on the Internet, starting with the basic concepts of the legal and institutional framework as well as the measures and tips on how to protect children and young people in the virtual world of the modern era. Since most world countries nowdays have the required legal regulation related to the protection of children on the Internet, this paper also includes a review of the legal framework, such as the United Nations Convention on the Rights of the Child adopted on 20th November 1989. and the Council of Europe Convention on the Protection of Children against Sexual Exploitation and Sexual Abuse adopted on 12th July 2007. Additionally, the Croatian legal framework has been analysed through laws that regulate the issue of the protection of children on the Internet. Firstly, the operations, measures and results of Croatian Institutions have been analysed, such as the Ministry of the Interior, the State Attorney's Office. Secondly, a number of institutions operating within the fields of education, health, social welfare and civil society as well as the state Ombudsman have been studied. Thirdly, other institutions working on preventive measures of protection, assistance to child victims and their families, programs or measures of intervention for perpetrators of sexual violence against children have also been taken under consideration. Finally, the measures, tips and ways to advise children and parents against Internet violence have been stated.