Background: Inadequate and inappropriate complementary feeding are major factors contributing to excess morbidity and mortality in young children in low resource settings. The early introduction of complementary feeds before the age of six months can lead to displacement of breast milk and increased risk of infections such as diarrhea, which further contributes to weight loss and malnutrition. Therefore the objective of this study is to assess early initiation of Complementary feeding and associated factors, in Kamba Woreda, South West Ethiopia. Methods: a community based cross sectional study was conducted in Kamba woreda, Gamo Gofa Zone, South West Ethiopia. The study was conducted on 562 mothers who have young child from 6 months to 2 years from December 2013 to January 2014 by using pre tested structured questioners. Univariate, bivariate and multivariate analysis was conducted by SPSS version 20. Results: From all respondents 59.6% started complementary feeding before six months. Age of mothers those who are in age group ≥30, AOR 2.60(1.07 - 6.35) years, Education level those who have no formal education AOR 2.76(1.63 - 4.69), occupational of mothers those who work as daily worker AOR 3.06(1.03 - 9.12)and Private work activity(merchant, farmers) AOR 2.39(1.61-3.53), Mothers who have no post natal follow up for their child in Health service AOR( 1.64(1.05 - 2.55) were significantly associated factors for early initiation of complementary feeding in the study area. Conclusion and Recommendation: - A relatively high proportion of mothers start early complementary feeding, despite what is recommended in the national and global infant and young child feeding guidelines. Maternal age, educational statues ,occupational statues, mothers who has no PNC, and mothers who encountered medical illness at post natal period were significant predictors for early initiation of complementary feeding.