BACKGROUND: Even though health care seeking interventions potentially reduce child mortality from easily treatable diseases, significant numbers of children die without ever reaching a health facility or due to delays in seeking care in Ethiopia. This study aimed to assess health care seeking behavior for common childhood illnesses and associated factors. METHODS: A community-based cross-sectional study was conducted in Jeldu District from January to February 2011. A systematic sampling method was used for sample selection. Data were collected from 422 caregivers with under-five children who experienced diseases within six weeks before the survey. Interviewer administered structured and pre-tested questionnaire which were used to collect data. Data entry and cleaning were carried out using Epi Info version 3.5.1 and analyzed using SPSS version 16. Descriptive analysis was done to determine the magnitude of health care seeking behavior. Multivariate logistic regression analyses were performed to identify associated factors. RESULTS: A total of 422 caregivers of under-five children were participated in the study giving an overall response rate of 97.5%. Three hundred fifteen (74.6%) children sought care from health facilities for all conditions. However, only 55.4% of them were taken to health facilities as first source treatment during their illness and prompt care was also very low (13.7%). Marital status of the caregivers (AOR = 2.84; 95%CI: 1.62-4.98), number of symptoms experienced by the child (AOR = 2.04; 95%CI: 1.24-3.36) and perceived severity of the illness (AOR = 3.20; 95%CI: 1.96-5.22) were predictors of health care seeking behavior. CONCLUSION: Health care seeking behavior for childhood illnesses was delayed and decision to seek care from health facilities was influenced by worsening of the illnesses. Thus, community level promotion of prompt health care seeking is essential to enhance the health care seeking behavior for child hood illnesses in the locality.