Background: The postpartum period is an important entry point for family planning service providers to reduce unintended and too closely spaced pregnancy. A postpartum modern contraceptive service is one of the recommended public health interventions for reducing maternal and child morbidity and mortalities. However, In Ethiopia modern contraceptive use during the postpartum period is low; resulting in unintended pregnancies and unwanted childbearing . there for this study was done to assess utilization and associated factors of modern contraceptives during the postpartum period among women who gave birth in the last 12 months in Injibara Town Awi Zone, North-Western Ethiopia. Methods: A Community based cross-sectional study design was conducted from March 01 to 15/2019 on 400 women who gave birth in the last 12 months preceding the survey. A simple random sampling technique was used to recruit study subjects. Data was collected using interviewer-administered pretested and structured questionnaires. Data were entered using Epi data 3.5 and exported to SPSS version 23 for analysis. The association between variables was analyzed using Bivariate and multivariable logistic regression models and p-value < 0.05 at 95% Confidence interval was considered as statistically significant. Result: The prevalence of modern contraceptive utilization was 58.5% (95% CI: 53.5- 63%) among postpartum mothers. Secondary school and higher educational levels [AOR= 5.02; 95% CI (1.53-16.47)],[AOR= 4.25; 95% CI:(1.32-13.64) respectively)], previous history of abortion [AOR= 3.93; 95%, CI: (1.43-10.84)], having three and four antenatal care visit [AOR= 4.74; 95%, CI: (1.94-11.54)] [AOR= 5.9; 95%, CI: (2.42-14.39) respectively], family planning counselling during antenatal care [AOR=2.81; 95% ,CI: (1.63- 4.86)], having postnatal care [AOR =1.79, 95%, CI: (1.09-2.96)], menses returning after birth [AOR=2.84, 95% CI: (1.77- 4.57)] and resuming sexual activity [AOR= 2.86, 95% CI: (1.71-4.78)] were factors affecting contraceptive use in postpartum period. Conclusion : The prevalence of modern contraceptive use among postpartum women was found to be high in Injibara town. Therefore, strengthen family planning counseling during antenatal care and postnatal care to reduce the missed opportunity of postpartum women to get family planning methods, especially long-acting reversible contraceptives.