Adolescence is one of the most critical and vulnerable stages of human development, marked by biological, psychological, and social changes that increase susceptibility to risky behaviors. Effective parent–adolescent communication regarding sexual and reproductive health is essential for promoting well-being and preventing adverse outcomes. Nevertheless, evidence shows that such communication remains limited in many societies, including that of Iran. This narrative review synthesized research from the past two decades to identify barriers and strategies for improving parent–adolescent dialogue on sexual matters. A comprehensive search was conducted across Persian and international databases for studies published between 2006 and 2025. Evidence indicates that parent–adolescent communication is restricted in most contexts. Barriers were classified into three domains: (1) cultural–religious (shame, taboos, fear of social judgment), (2) psychological–communicative (fear of encouraging sexual activity, parents’ limited knowledge, lack of communication skills), and (3) generational–social (digital divide, weak paternal involvement, reduced family interactions). Recent studies have also highlighted social media use and evolving family lifestyles as emerging challenges. In conclusion, parent education, greater involvement of fathers, school-based initiatives, and sociocultural interventions can help overcome communication barriers. Family centered workshops and improved parental media literacy are key strategies for enhancing sexual communication within families.