Objective: The purposes of this study were to (a) examine the effectiveness of registered dietitian (RD) education and counseling on diet-related patient outcomes compared with general education provided by the cardiac rehabilitation (CR) staff, and (b) evaluate the effectiveness of the Meats, Eggs, Dairy, Fried foods, In baked goods, Convenience foods, Table fats, Snacks (MEDFICTS) score as an outcome measure in CR. Methods: Observational study data examined from 426 CR patients discharged between January 1996 and February 2004. Groups were formed based on education source: (a) RD and (b) general education from CR staff. Baseline characteristics were compared between groups; pre/post diet-related outcomes (lipids, waist circumference, body mass index, MEDFICTS score) were compared within groups. Controlling for baseline measures and lipid-lowering medication, associations were examined between (a) RD education and diet-related outcomes and (b) ending MEDFICTS score and diet-related outcomes. Results: Mean age was 62±11 years, 30% of patients were female, and 28% were nonwhite. At baseline, the RD group (n=359) had more dyslipidemia (88% vs 76%), more obesity (47% vs 27%), a larger waist (40±6 vs 37±5 inches), a higher body mass index (calculated as kg/m2; 30±6 vs 27±5), a higher diet score (32±28 vs 19±19), and lower self-reported physical activity (7±12 vs 13±18 metabolic equivalent hours) (all P<.05) than the general education group (n=67). RD education was associated with improved low-density lipoprotein (r=0.13; P=.04), triglycerides (r=0.48; P=.01), and MEDFICTS score (r=0.18; P=.01). Improvements in MEDFICTS scores were correlated with improved total cholesterol, triglycerides, and waist measurements (all r=0.19; P=.04). Conclusions: Dietary education by an RD is associated with improved diet-related outcomes. The MEDFICTS score is a suitable outcome measure in CR. Copyright © 2005 by the American Dietetic Association.