BACKGROUND: Group education for patients with suboptimally controlled diabetes has not been rigorously studied. METHODS: A total of 623 adults from Minnesota and New Mexico with type 2 diabetes and glycosylated hemoglobin (HbA(1c)) concentrations of 7% or higher were randomized to (1) group education (using the US Diabetes Conversation Map program), (2) individual education, or (3) usual care (UC; ie, no assigned education). Both education methods covered content as needed to meet national standards for diabetes self-management education and were delivered through accredited programs from 2008 to 2009. General linear mixed-model methods assessed patient-level changes between treatment groups in mean HbA(1c) levels from baseline to follow-up at 6.8 months. Secondary outcomes included mean change in general health status (Medical Outcomes Study 12-Item Short Form Health Survey [SF-12]), Problem Areas in Diabetes (PAID), Diabetes Self-Efficacy (DES-SF), Recommended Food Score (RFS), and Physical Activity (PA, min/wk). RESULTS: Mean HbA(1c) concentration decreased in all groups but significantly more with individual (-0.51%) than group education (-0.27%) (P = .01) and UC (-0.24%) (P = .01). The proportion of subjects with follow-up HbA(1c) concentration lower than 7% was greater for individual education (21.2%) than for group (13.9%) and UC (12.8%) (P = .03). Compared with UC, individual education (but not group) improved SF-12 physical component score (+1.88) (P = .04), PA (+42.95 min/wk) (P = .03), and RFS (+0.63) (P = .05). Compared with group education, individual education reduced PAID (-3.62) (P = .02) and increased self-efficacy (+0.1) (P = .04). CONCLUSIONS: Individual education for patients with established suboptimally controlled diabetes resulted in better glucose control outcomes than did group education using Conversation Maps. There was also a trend toward better psychosocial and behavioral outcomes with individual education. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00652509.