The feasibility and effectiveness of a distance-based quality improvement model were examined in a cohort of Pediatric Research in Office Settings (PROS) practices, with the goal of improving immunization rates and practitioner behaviors and attitudes. Of an initially assessed 82 practices, 29 with baseline rates of < or =88% for children 8 to 15 months of age were randomized into year-long paper-based education or distance-based quality improvement intervention groups. Outcomes were utility/helpfulness of quality improvement modalities, immunization rate change, and behavior/attitude change. Quality improvement participants attended approximately 75% of monthly conference calls but used the quality improvement Listserv and Web site infrequently (mean 1.09 and 0.92 uses, respectively). Helpfulness ratings of quality improvement modalities mirrored usage. Analyses revealed a 4.9% increase in quality improvement group immunization rates (P = .061), a 0.8% education group increase (P = .752), and a 4.1% difference between groups (P = .261). More quality improvement practices adopted systems identifying children behind in immunizations. A distance-based quality improvement model is feasible and may improve immunization rates.