Purpose: Little is known about how electronic mail (e-mail) is currently used in oncology practice to facilitate patient care. The objective of our study was to understand the current e-mail practices and preferences of patients and physicians in a large comprehensive cancer center. Methods: Separate cross-sectional surveys were administered to patients and physicians (staff physicians and clinical fellows) at the Princess Margaret Cancer Centre. Logistic regression was used to identify factors associated with current e-mail use. Record review was performed to assess the impact of e-mail communication on care. Results: The survey was completed by 833 patients. E-mail contact with a member of the health care team was reported by 41% of respondents. The team members contacted included administrative assistants (52%), nurses (45%), specialist physicians (36%), and family physicians (18%). Patient factors associated with a higher likelihood of e-mail contact with the health care team included younger age, higher education, higher income, enrollment in a clinical trial, and receipt of multiple treatments. Eighty percent of physicians (n = 63 of 79) reported previous contact with a patient via e-mail. Physician factors associated with a greater likelihood of e-mail contact with patients included older age, more senior clinical position, and higher patient volume. Nine hundred sixty-two patient records were reviewed, with e-mail correspondence documented in only 9% of cases. Conclusion: E-mail is commonly used for patient care but is poorly documented. The use of e-mail in this setting can be developed with appropriate guidance; however, there may be concerns about widening the gap between certain groups of patients.