The purpose of this study is to examine the association of ethnicity and language concordance with physician-patient agreement about physicians' recommendations for patient health behavior in the following areas: diet, exercise, medication, smoking, stress, and weight. Twenty-seven resident physicians at the University of New Mexico's internal medicine and family practice clinics and 427 of their patients participated. Random effects models were used to estimate the influence of ethnicity and language concordance on whether patients and physicians agreed about specific recommended changes in patient behavior. Ethnicity concordance was not significantly associated with physician-patient agreement. Language concordance positively influenced the likelihood of agreement about exercise but negatively influenced agreement about medications. The lowest percentage of agreement occurred in the area of medication regimens (60%). The results from this study indicate that language is an important barrier to physician-patient agreement, while ethnicity concordance has no effect. However, the influence of whether the physician and patient speak the same language on agreement is unclear and warrants further research.