Objective: To test the effect of three questions (what are my options? what are the benefits and harms? and how likely are these?), on information provided by physicians about treatment options. Methods: We used a cross-over trial using two unannounced standardized patients (SPs) simulating a presentation of mild-moderate depression. One SP was assigned the intervention role (asking the questions), the other the control role. An intervention and control SP visited each physician, order allocated randomly. The study was conducted in family practices in Sydney, Australia, during 2008-09. Data were obtained from consultation audio-recordings. Information about treatment options and patient involvement were analyzed using the Assessing Communication about Evidence and Patient Preferences (ACEPP) tool and the OPTION tool. Results: Thirty-six SP visits were completed (18 intervention, 18 control). Scores were higher in intervention consultations than controls: ACEPP scores 21.4 vs. 16.6, p< 0.001, difference 4.7 (95% CI 2.3-7.0) and OPTION scores 36 vs. 25, p= 0.001, difference 11.5 (95% CI 5.1-17.8), indicating greater information provision and behavior supporting patient involvement. Conclusion: Asking these three questions improved information given by family physicians and increased physician facilitation of patient involvement. Practice implications. These questions can drive evidence-based practice, strengthen patient-physician communication, and improve safety and quality.