An 8-week educational intervention focusing on low-fat eating pattern messages was conducted among employees of the city of Phoenix, Arizona. One hundred nineteen employees with serum cholesterols of > or = 5.2 mmol/liter who participated in at least one of eight weekly sessions were compared with 112 nonparticipants. Multiple regression analysis indicated significant intervention effects. For participants, total blood cholesterols decreased an average of 0.22 mmol/liter, low-density lipoproteins (LDLs) decreased an average of 0.30 mmol/liter, and triglycerides decreased an average of 1.91 mmol/liter. High-density lipoproteins (HDLs) increased an average of 0.68 mmol/liter. Significant effects remained after considering initial lipid status, and variation in age, sex, occupation, ethnicity, alcohol intake, fat intake, and BMI. These results constitute a 3.8% decrease in serum cholesterol and a 7.8% decrease in LDLs.