The purposes of this study were to test the ability of tailored interventions to raise influenza immunization rates and assess the effect on timely receipt of other vaccines. We conducted a before/after trial over 2 years to increase influenza vaccination rates of patients 6-23 months old in five inner-city family health centers serving low-income children with a sixth site as a concurrent control. Influenza vaccination rates improved significantly from a baseline of 4.7-24.7% in the first year and 36.6% in the second year, P < 0.001. The increase in rates was greater in intervention sites than the control site (31.9% versus 25.7%, P = 0.02). In regression analyses of influenza vaccination, intervention year was associated with an odds ratio (OR) of 9.4 (95% confidence interval (CI) = 4.4-20.0) for the first intervention year and OR = 13.4 (95% CI = 6.5-28.0) for the second intervention year. Children vaccinated against influenza were more likely to have received DTaP 3 and MMR within 2 months of the recommended age than children not vaccinated against influenza (P < 0.001).