Background. Open family discussion on reproductive health (RH) issues often leads to increased awareness on RH matters and reduces risky behaviors among adolescents. This study was conducted to assess factors affecting parent-adolescent discussion on RH issues in Harar, Ethiopia. Methods. A cross-sectional survey using face to face interview supplemented with focus group discussion (FGD) was conducted on 751 randomly selected parents of 10–19-year-old adolescents. Data was analyzed using SPSS version 15. Results. More than one-fourth (28.76%) of parents reported discussing RH issues with their adolescents during the last six months. In the logistic regression, parents who have demonstrated good RH knowledge and positive attitude towards RH were almost six times and seventy percent (AOR 5.69, 95% CI: 3.67–8.82; AOR 1.70, 95% CI: 1.08–2.68) higher in discussing RH with their adolescents than their counterparts, respectively. Conclusion. Parent-adolescent discussion about RH issues rarely occurs and is bounded by lack of knowledge, sociocultural norms, and parental concern that discussion would encourage premarital sex. Reproductive health programs should target on improving awareness of parents and addressing sociocultural norms surrounding reproductive health issues.