Objectives: A survey was conducted to estimate the prevalence of self-medication with antibiotics in Jordan and evaluate the factors associated with antibiotic misuse. Methods: Validated questionnaire was used to collect data from a sample of 1943 households (9281 persons) selected from among different cities in Jordan. Results: 842 (39.5%) of 2133 antibiotic users identified via the survey had used antibiotics without a prescription within a one-month study period. Self-medication with antibiotics was found to be significantly associated with age, income, and level of education. The main reason for self-medication as reported by the participants was their previous experience on the efficacy of treatment. The main sources of antibiotics were the previously prescribed pharmaceuticals stored in the household and those purchased in pharmacies. Conclusion: The prevalence of self-medication with antibiotics in Jordan is alarmingly high. Given the growing global resistance to antibiotics and the documented health problems related to their inappropriate use, our findings may have major public health policy implications in Jordan.