Objectives To assess the occurrence of questions that foster shared decision making, in particular cancer patients' understanding of treatment decisions and oncologists' understanding of patients' priorities, during consultations in which preference‐sensitive decisions are discussed. Specifically, (a) regarding patient understanding, do oncologists ask about patients' preexisting knowledge, information preferences, and understanding and do patients and companions ask about the disease and treatment, and (b) regarding patient priorities, do oncologists ask about patients' treatment‐ and decision‐related preferences and do patients and companions ask about the decision? Methods Audiotaped pretreatment consultations of 100 cancer patients with 32 oncologists about (neo)adjuvant treatment were coded and analyzed to document question type, topic, and initiative. Results The oncologists ascertained prior knowledge in 50 patients, asked 24 patients about preferred (probability) information, and invited questions from 56 patients. The oncologists asked 32 patients about treatment preferences and/or for consent. Respectively, one‐third and one‐fifth of patients and companions asked about treatment benefits compared with three‐quarters of them who asked about treatment harms and/or procedures. Conclusions It would be helpful to patients if oncologists more often assessed patients' existing knowledge to tailor their information provision. Also, patients could receive treatment recommendations that better fit their personal situation if oncologists collected information on patients' views about treatments. Moreover, by educating patients to ask about treatment alternatives, benefits, and harms, patients may gain a better understanding of the choice they have.