BackgroundExclusive breastfeeding is giving only breast milk to an infant from birth up to six months of age, with the exception of medications and vitamins. For the first six months of life, breast milk alone is the ideal nourishment to meet the nutritional demand of the growing child. Although breastfeeding is a universal practice, in Ethiopia only 52% of children aged less than six months old were exclusively breastfed. The study aimed to investigate the predictors of exclusive breastfeeding duration among women who had children aged between 6–12 months in Gurage zone, South Ethiopia.MethodsA mixed method cross-sectional study was conducted to assess predictors of exclusive breastfeeding duration in south Ethiopia. Eight hundred and twenty eight study participants were recruited using a multistage sampling technique for the quantitative survey. Interviewer administered close ended questionnaire was used to collect the quantitative data. Data were entered using Epi Data and analyzed using SPSS version 21. The Kaplan-Meier curve with log rank test was used to compare the survival difference due to the selected covariates. A binary and multivariable Cox regression model was used to identify the independent predictors of exclusive breastfeeding duration. Three focus group discussions were conducted to generate the qualitative data. Qualitative data is transcribed and analyzed by thematic approach using open-code software.ResultsThe median duration of exclusive breastfeeding was six months. About 21.9% of women introduced complementary food before six months of child age. Women with education status of diploma and above (Adjusted Hazard Ratio [AHR]: 2.89, 95% CI: 1.05, 7.97), perceived inadequate breast milk (AHR: 11, 95% CI: 6.7, 18.0) and cesarean section delivery (AHR: 3.8, 95% CI: 2.0, 7.2) were more likely to cease exclusive breastfeeding before six months of child age; while women who had infant feeding counseling during postnatal care (AHR: 5.1, 95% CI: 2.5, 10.23) were less likely to cease exclusive breastfeeding before the child was six months of age.ConclusionsA significant proportion of women cease exclusive breastfeeding before the recommended six months duration. Maternal education of diploma and above, perceived inadequacy of breast milk, cesarean section delivery, postnatal counseling on child feeding are factors significantly associated with the duration of exclusive breastfeeding. Encouraging behavioral change and improving communication regarding the duration of exclusive breastfeeding, and increasing the utilization of postnatal counseling about exclusive breastfeeding are recommended.