The purpose of this study was to examine the relationship between mood states and β-adrenergic receptor function in a normal population. We also examined if sympathetic nervous system activity is related to mood states or β-adrenergic receptor function. Sixty-two participants aged 25-50 years were enrolled in this study. Mood states were assessed using the Profile of Mood States (POMS). β-adrenergic receptor function was determined using the chronotropic 25 dose isoproterenol infusion test. Level of sympathetic nervous system activity was estimated from 24-hr urine norepinephrine excretion. Higher tension-anxiety, depression-dejection, and anger-hostility were related to decreased β-adrenergic receptor sensitivity (i.e., higher chronotropic 25 dose values), but tensionanxiety was the only remaining independent predictor of β-adrenergic receptor function after controlling for age, gender, ethnicity, and body mass index (BMI). Urinary norepinephrine excretion was unrelated to either mood states or β-adrenergic receptor function. These findings replicate previous reports that anxiety is related to decreased (i.e., desensitized) β-adrenergic receptor sensitivity, even after controlling for age, gender, ethnicity, and body mass index.