BackgroundOptimal complementary feeding alone prevents six percent of child mortality, but it has continued to be considered as sub-optimal in Ethiopia. Therefore, this study aimed to assess timely initiation of complementary feeding and associated factors among mothers with children aged 6–23 months in Lalibela District.MethodsA community-based cross-sectional study was conducted from March 01 to April 29, 2015. Four hundred twenty-one mother-child pairs were selected by the systematic random sampling technique. An interviewer-administered questionnaire was used to collect data. A multivariable logistic regression analysis was employed to identify factors associated with timely initiation of complementary feeding. The Adjusted Odds Ratio (AOR) with a 95 % Confidence Interval (CI) was computed to assess the strength of association, and variables with a P-value of <0.05 were considered as statistically significant in the multivariable analysis.ResultsThe study demonstrated that, the prevalence of timely initiation of complementary feeding was 63 %. In addition, mother’s education [AOR = 4.33, 95 % CI: 1.99, 9.40], antenatal care follow up [AOR = 5.90, 95 % CI: 2.45, 14.21], and institutional delivery [AOR = 2.54, 95 % CI: 1.33, 4.82] were found key determinants of timely initiation of complementary feeding.ConclusionIn this community, timely initiation of complementary feeding was lower than the World Health Organization cut-off point for good practice of complementary feeding. Therefore, intensifying utilization of antenatal care and institutional delivery helps to improve the coverage of timely initiation of complementary feeding. Furthermore, the focus needs to be on uneducated women.