ABSTRACT PURPOSE The purpose of this study was to ascertain physician characteristics associated with exploring suicidality in patients with depressive symptoms and the influence of patient antidepressant requests. METHODS Primary care physicians were randomly recruited from 4 sites in northern California and Rochester, NY; 152 physicians participated (53%-61% of those approached). Standardized patients portraying 2 conditions (major depres- sion and adjustment disorder) and 3 antidepressant request types (brand specific, general, or none) made unannounced visits to these physicians between May 2003 and May 2004. We examined factors associated with physician exploration of suicidality. RESULTS Suicide was explored in 36% of 298 encounters. Exploration was more common when the patient portrayed major depression (vs adjustment disorder) (P=.03), with an antidepressant request (vs no request) (P=.02), in academic settings (P<.01), and among physicians with personal experience with depres- sion (P<.01). The random effects logistic model revealed a significant physician variance component with ρ=0.57 (95% confidence interval, 0.45-0.68) indicat- ing that there were additional, unspecified physician factors determining the ten- dency to explore suicide risk. These factors are unrelated to physician specialty (family medicine or internal medicine), sex, communication style, or perceived barriers to or confidence in treating depression. CONCLUSIONS When seeing patients with depressive symptoms, primary care physicians do not consistently inquire about suicidality. Their inquiries into sui- cidal thinking may be enhanced through advertising or public service messaging that prompts patients to ask for help. Research is needed to further elucidate physician characteristics associated with the assessment of suicidality.