This study aimed to examine the effective parental impact in preventing problematic smartphone use in adolescents by identifying the parent-related factors. A secondary analysis of cross-sectional data from a Korean national survey was conducted. Data from 2758 male and 2419 female adolescents, aged 10 to 19 years, were analyzed; the respondents were divided into normal and risk groups based on their standardized smartphone addiction diagnostic scale scores. Parent-related factors of smartphone addiction were analyzed using a logistic regression model. Among both male and female adolescents, mobile messenger usage, and family environment emerged as significant predictors of problematic smartphone use. In addition, for male adolescents, smartphone use frequency and parent's awareness of content use were significant predictors. The findings indicated the importance of parental roles in preventing problematic smartphone use in adolescents. Parents should create a healthy family environment by avoiding smartphone overuse and modeling the appropriate usage of smartphones.