Introduction: The concept of behavioral addictions includes also internet use. Internet addiction is one of the most frequently declined nonsubstance addictions within general population. Sample and methods: The survey included 315 hospitalized patients with alcohol dependence, drug dependence and pathological gambling. The questionnaire was used to find out the prevalence of internet addiction and intensity of internet use. Results: We found internet addiction in one patient with combined substance dependence. The patients with pathological gambling used internet for the longest time within a day. Conclusion: The prevalence of internet addiction found in the survey was lower than in other studies.

Key words: internet – addiction – alcohol – drugs – pathological gambling