Background: Mother to child transmission is responsible for 90% of child infection with human immune deficiency virus (HIV). Dual contraceptive use is one of the best actions to prevent mother's human immune deficiency virus transmission to her child and partner. This study aimed at assessing the prevalence and factors associated with dual contraceptive use among sexually active women on antiretroviral therapy in Gondar City, northwest, Ethiopia. Methods: An institution based cross sectional study was conducted in Gondar City public health facilities from December 1 to 31, 2018. Systematic random sampling technique was utilized to include 563 study participants. Data were collected by interview using a structured questionnaire. Descriptive analysis was made to compute mean, median and proportion. Finally, multivariable logistic regression model was fitted to identify the factors associated with dual contraceptive method utilization. Analysis was performed by using Statistical Package for Social Sciences (SPSS) software version 20. Results: The overall prevalence of dual contraceptive method utilization among sexually active women on antiretroviral therapy was 28.8% (95% CI: 24.9, 32.7). Women aged 35-49 years (Adjusted odds ratio (AOR): 6.99; 95% CI: 3.11, 15.71)), who lived in urban areas (AOR: 4.81; 95% CI: 2.04, 11.31), attended secondary and above education (AOR: 4.43; 95% CI: 1.92, 10.22), and disclosed HIV status to sexual partners (AOR: 9.84; 95% CI: 3.48, 27.81) were more likely to use dual contraceptive method. Conclusion: In this study, the proportion of women who utilized dual contraceptive method was low. Age, place of residence, educational status and disclosure of HIV status were factors associated with dual contraceptive use. Therefore, providing education about the advantages of disclosing HIV status to sexual partners and strengthening of counseling about the advantages of dual contraceptive use will be helpful in enhancing the use of dual contraceptive method among sexually active women on antiretroviral therapy.