OBJECTIVE To determine the prevalence of medical errors related to the discontinuity of care from an inpatient to an outpatient setting, and to determine if there is an association between these medical errors and adverse outcomes. PATIENTS Eighty-six patients who had been hospitalized on the medicine service at a large academic medical center and who were subsequently seen by their primary care physicians at the affiliated outpatient practice within 2 months after discharge. DESIGN Each patient’s inpatient and outpatient medical record was reviewed for the presence of 3 types of errors related to the discontinuity of care from the inpatient to the outpatient setting: medication continuity errors, test follow-up errors, and work-up errors. MEASUREMENTS Rehospitalizations within 3 months after the initial postdischarge outpatient primary care visit. MAIN RESULTS Forty-nine percent of patients experienced at least 1 medical error. Patients with a work-up error were 6.2 times (95%confidence interval [95% CI], 1.3 to 30.3) more likely to be rehospitalized within 3 months after the first outpatient visit. We did not find a statistically significant association between medication continuity errors (odds ratio [OR], 2.5; 95%CI, 0.7 to 8.8) and test follow-up errors (OR, 2.4; 95%CI, 0.3 to 17.1) with rehospitalizations. CONCLUSION We conclude that the prevalence of medical errors related to the discontinuity of care from the inpatient to the outpatient setting is high and may be associated with an increased risk of rehospitalization.