Background: Patient-reported outcomes and wearable sensor measures of physical function can predict important outcomes in oncology. However, mobile and wearable-sensor apps collect vast information from patients and caregivers; indiscriminate reporting may increase provider burden and reduce data reliance. This study aimed to assess medical oncologists’ current practices in utilizing such information, and their data delivery preferences. Methods: Cross-sectional survey delivered by email to all Kaiser Permanente Northern California medical oncologists, February-March 2021. Results: Thirty-eight oncologists (30% of 127) responded to the survey. Most agreed that to reduce adverse events (AEs) it is important for the oncologist to know about the following measures: 1) patient/caregiver-reported physical symptoms (92% responded either very important or essential); 2) patient/caregiver-reported physical function (87%); and 3) objective measures of gait/balance (55%) and physical activity (50%) obtained from wearable sensors. Similarly, most respondents strongly consider these data when making decisions related to treatment intent, dosage, or visit frequency. All respondents routinely rely on information from caregivers, and in case of a discrepancy, more rely on the caregiver’s report (45%) than the patient’s report (8%), and some seek additional objective information (26%). Most respondents indicated that they prefer to receive electronic information on physical function and symptoms only for “critical values” and/or to have the information accessible “as needed” in the electronic chart, but not actively delivered to them (Table). Conclusions: Oncologists believe that patient/caregiver reports of symptoms and physical function can predict AEs, and strongly rely on them in clinical decision making. The majority of respondents would like to have access to physical function/symptoms data from mobile/wearable apps, with more providers wishing to receive information prior to a visit and/or in case of “critical values”. These findings may inform future implementations of mobile/wearable technologies to track symptoms and function of cancer patients.