Aim: The aim of the paper was to investigate the relationships between introducing family rules for phone and computer use, compliance with these rules and the frequency and methods of electronic media use, health, life satisfaction and relationships of adolescents with their parents. Materials and methods: An anonymous survey was conducted in Poland among 844 students aged 10–18 years (55.3% boys; 28.0% were primary school students, 42.3% were lower secondary school students, 29.7% were upper secondary school students; 45.3% were residents of big cities, with populations of over 100,000, 23.1% were residents of small towns and 31.6% were rural residents). The questionnaire included questions and scales relating to electronic media use (different activities and rules for the use of electronic media), health (self-rated health, subjective health complaints, life satisfaction) and family relations (clear communication, social support and shared activities). Results: A total of 97.7% of adolescents have access to a computer at home (no difference in terms of gender, age and place of residence), while 80.7% of adolescents have a computer or a laptop for their own exclusive use (the percentage grows with the level of education, from 77.4% to 87.6%); 87.4% of respondents own a device with Internet access, 97.1% have a mobile phone (girls slightly more often than boys: 98.6% vs. 95.8%). Adolescents who fail to comply with family rules on the use of electronic media dedicate the most amount of time to use these media for entertainment and face the most serious health and social consequences. Introduction of time restrictions by parents reduces the time devoted by adolescents to electronic media, but only the time spent on entertainment. Conclusions: Introduction and consistent compliance with the rules for using electronic media are important for good family relationships and are associated with clear communication, support, and spending time with parents.