BackgroundPostpartum period is an important entry point for family planning service provision; however, women in Ethiopia are usually uncertain about the use of family planning methods during this period. Limited studies have been conducted to assess postpartum family planning use in Addis Ababa, in particular and in the country in general. So, this study was conducted to assess postpartum family planning use and its associated factors among women in extended postpartum period in Kolfe Keranyo sub city of Addis Ababa.Materials and methodsA community-based cross sectional study was conducted from May to June 2015 on 803 women who have had live births during the year (2014) preceding the data collection in the sub city. The multi-stage cluster sampling technique was used to select study participants. Data were collected by interviewer administered structured questionnaire, entered into EPI INFO version 7 and analyzed by SPSS Version 20. Bivariable and Multivariable logistic regression models were employed to see the presence and strength of the association between the dependent and independent variables by computing the odds ratios with a 95% confidence intervals and p-values.ResultsThe prevalence of postpartum family planning use was 80.3% (95% CI: 74.5, 83.1). Marriage, (AOR 0.09, 95% CI: 0.03, 0.22), menses resumption after birth, (AOR 2.12, 95% CI: 1.37, 3.41), length of time after delivery, (AOR 2.37, 95% CI: 1.18, 4.75), and history of contraceptive use before last pregnancy, (AOR 0.12, 95% CI: 0.07, 0.18) were the factors associated with postpartum family planning use.ConclusionThe prevalence of postpartum family planning use was high and the main factors associated with it were marriage, menses resumption, length of time after delivery, and history of previous contraceptive use. Therefore women should get appropriate information about the possibility of exposure to pregnancy prior to menses resumption by giving special emphasis to those who had no previous history of contraceptive use and exposure to the other identified factors.