The primary goals of this study were to examine: (1) whether patients were involved actively in initiating the prescribing of psychotropic medications during interactions with their primary care physicians and (2) what variables influenced patient vs physician initiation of psychotropic prescribing. An analysis of 508 audiotapes of physician-patient interactions and interviews with each patient and physician from 11 different ambulatory care settings was conducted. Of 508 patients, 17% (n = 88) received prescriptions for one or more psychotropic medications. Forty-seven percent of repeat psychotropic prescriptions and 20% of new psychotropic prescriptions were initiated by patients. Logistic regression techniques showed that patients with higher incomes were more likely than their physicians to initiate psychotropic prescribing, whereas physicians were more likely to initiate psychotropic prescribing with lower income patients (P < 0.001). Patients who had more previous visits to their physician were as likely as their physicians to initiate psychotropic prescribing, whereas physicians were more likely to initiate psychotropic prescribing with patients who had been to see them fewer times in the past (P < 0.05).