In a culturally competent diabetes self-management intervention in Starr County, Texas, bilingual Mexican American nurses, dieticians, and community workers provided weekly instruction on nutrition, self-monitoring, exercise and other self-care topics. A biweekly support group promoted behavior change. Interviews and examinations with 256 Mexican American diabetic year-long participants found significantly lower levels of blood glucose and higher diabetes knowledge scores. (Contains 28 references.) (TD)