Individuals who are addicted to one addiction are at an increased risk for developing another new addiction. New-onset addictions among patients with alcohol dependence needs to be considered for more effective treatment of alcohol dependence. In this cross-sectional study, Japanese outpatients with alcohol dependence were assessed using a comprehensive, originally designed questionnaire to determine whether they were addicted to substances or behaviors other than alcohol. The prevalence rates of new-onset addictions were compared between alcohol-dependent patients who had abstained from alcohol for a year or more and those who had not. Multiple regression analysis was performed to examine the association between the number of new-onset addictions and the demographic and clinical characteristics. One hundred and nine outpatients with alcohol dependence (54.6±11.0 years; 97 men) participated in the study. The prevalence of new-onset addictions was 41.3%. No significant differences were found in the prevalence of new-onset addictions between the patients who had abstained for a year or more and those who had not. Multiple regression analysis revealed that the number of new-onset addictions was positively associated with the presence of psychiatric comorbidity (β = 0.24; p = 0.02) and use of benzodiazepines (β = 0.20; p = 0.04) with a R2 of 0.153. Alcohol dependent patients with characteristics such as psychiatric comorbidity and use of benzodiazepines should be given more attention to the development of new-onset addictive behaviors. On the other hand, those behaviors could be acceptable for harm-reduction unless excessive and loss of control.