OBJECTIVES: Hospital readmissions, defined as 30-day post-discharge readmission, are used for assessing the performance of a healthcare system and are quality indicators of patient care. This study examined the relationship between readmissions and patient- and county-level variables using multi-level analyses. METHODS: A retrospective cohort approach with a baseline and a follow-up period was used. Patient-level data were derived from multi-state Medicaid claims for the period between 2006 and 2008.  County-level variables were derived from the Area Health Resource File of 2007. The study cohort consisted of non-elderly (21-64 years) Medicaid beneficiaries with selected chronic conditions, who were alive and had continuous fee-for-service enrollment through the observation period and were not enrolled in Medicare and had at least one inpatient encounter in the follow up period (N=15,806).  The dependent variable, 30-day readmission was calculated in the follow-up year as those with an inpatient admission within 30-days from the discharge date of the first observed hospitalization.  Multi-level logistic regressions that accounted for beneficiaries nested within counties was used to examine the factors associated with 30-day readmissions. RESULTS: In this study population 16.7% had all-cause 30-day readmissions.  Hispanics were less likely to have 30-day readmission as compared with Caucasians [AOR=0.80, 95% CI 0.70,0.92].  Adults with asthma [AOR=1.16, 95% CI 1.03,1.32], dementia [AOR=1.44, 95% CI 1.10,1.87], and stroke [AOR=1.38, 95% CI 1.07,1.78] were more likely to have 30-day readmission and those with cardiac arrhythmia [AOR = 0.82, 95% CI 0.68,0.99] and hypertension [AOR=0.85, 95% CI 0.76,0.94] were less likely to have 30-day readmissions. Adults with greater lengths of stay during the index hospitalization were more likely to have 30-day readmissions [AOR = 1.03, 95% CI 1.03,1.04]. CONCLUSIONS: Patient-level factors were associated with the risk of 30-day readmissions. Programs designed to reduce the risk of 30-day readmissions may need to focus on appropriate disease management.