Background: Dual contraceptive method use is defined as the use of any modern contraceptive method with a condom for the reduction of mother-to-child transmission of HIV and sexually transmitted infections between sexual partners. The goal of this study was to assess the proportion and factors associated with dual contraceptive use among reproductive age women on antiretroviral therapy in Borena district, Northeast Ethiopia. Objective: To assess the proportion of dual contraceptive use and associated factors among the reproductive age women on antiretroviral therapy in Borena district, Northeast Ethiopia. Methods: An institutional-based cross-sectional study was conducted among HIV positive reproductive age group women on antiretroviral therapy in Borena district from February 1 to March 1, 2020. A systematic random sampling technique was used to include 417 study participants. A structured interviewer-administered questionnaire was used to collect the data. A binary logistic regression model was used to identify the factors associated with dual contraceptive use. Odds ratio with 95% confidence interval (CI) and P-value were calculated to assess the strength of association. Results: The results showed that 19.4% of the HIV positive reproductive age group on antiretroviral therapy were using dual contraceptive method. Urban area (AOR=3.66, 95% CI=1.66-8.09), educated to secondary education and above (AOR=3.54, 95% CI=1.29-9.76), those who have no desire to have a child (AOR=4.41, 95% CI=2.66-7.59), those with partners whose HIV status was negative (AOR=4.96, 95% CI=2.66-12.02) and those with partners whose HIV status was positive (AOR=2.45, 95% CI=1.25-4.81) were more likely to use the dual contraception method. Conclusion: This study showed that the proportion of dual contraceptive use was found to be low in accordance with the WHO recommendation. Therefore increased awareness on the advantages of dual contraception and knowing partner's HIV status is important.