PURPOSE: Immunization rates in many cities in the United States remain suboptimal compared to Healthy People 2020 Goals and are lower than national averages. This study aimed to determine whether a lecture-based educational intervention targeted at nurses and medical assistants would improve vaccination rates. METHODS: We conducted a quality improvement study in two urban academic family medicine clinics serving a predominantly Medicaid patient population as well as a sizable proportion of refugees. The intervention consisted of 3 lectures that were delivered to clinic nurses and medical assistants. Vaccinations in 1689 patients - 872 in the 3-month preintervention period, 817 in the 3-month postintervention period - were analyzed. RESULTS: Following the educational intervention, a statistically significant increase was seen only in human papillomavirus vaccine immunization rates for 13-18-year-olds (from 90.7% [n=54] to 100% [n=45]; P=0.036). When the results were stratified by clinic, only 1 site showed statistically significant increases in: pneumococcal polysaccharide vaccine (23-valent) for high-risk 19-to-64-year-olds (from 36.4% [n=154] to 47.8% [n=136]; P=0.049); Haemophilus influenzae type B vaccine for 2-month-to-5-year-olds (from 91.1% [n=112] to 97.3% [n=111]; P=0.048); and meningococcal conjugate vaccine (quadrivalent) for 13-18-year olds (from 85.2% [n=27] to 100% [n=26]; P=0.042). No increases were seen for our study's refugee patient population (n=171), and a significant decrease of the second-dose measles, mumps, and rubella vaccine (P=0.036) occurred in this subcohort. CONCLUSIONS: Ultimately, this quality improvement study demonstrated that educational interventions alone have a limited impact on increasing immunization rates.