Introduction:In developing countries, inadequate knowledge on complementary feeding (CF) is one of the main reasons for malnutrition Objective: To assess the knowledge on CF among parents of children aged 4 to 12 months attending a base hospital in a rural district in Sri Lanka.Method: A descriptive cross sectional study was conducted in the paediatric ward and clinic of Base Hospital Bibile from April to June, 2016. A total of 383 parents of babies aged 4-12 months were selected by consecutive sampling. Their knowledge regarding CF was assessed by using a structured, pre-tested, interviewer-administered questionnaire. Questions were classified as 'must know', 'better to know' and 'good to know'. Results:The response rate was 100%. Mean total knowledge score was 33.79 ± 4.3 (total 49) and the distribution was positively skewed. Mean knowledge scores were 7.08 ± 1.95 (total 11), 9.67 ± 1.88 (total 15), 17.03 ± 2.08 (total 23) in 'must know', 'better to know' and 'good to know' sections respectively. A significant correlation was only observed between age of the child and the total knowledge score (p<0.05). Only ethnicity (p<0.005) and religion (p<0.05) were significantly associated with total knowledge scores. Multiple logistic regression revealed only family income as a predictor for satisfactory knowledge among parents. Conclusions:Parents of children aged 4 to 12 months attending Base Hospital, Bibile had satisfactory knowledge on CF.