Background: Patient access to health information using electronic patient portals is increasingly common. Portal use has the potential to improve patients' engagement with their health and is particularly important for patients with chronic illness; however, patients’ abilities, attitudes, and use of portals is poorly understood. Methods: A single-center, cross-sectional survey was conducted of 240 consecutive pre- and post-kidney transplant patients of all levels of technological proficiency who presented to an urban transplant center in the United States. The Patient Information and Technology Assessment-Patient Portal (PITA-PP) was used to assess patients' attitudes toward the use of patient portals. Results: Most patients surveyed did not use the patient portal (n = 176, 73%). Patients were more likely to use the patient portal if they were White, highly educated, in the post-transplant period, more comfortable with technology, and reported being a frequent internet user (p < 0.05). The most common reasons for not using the patient portal included: (1) preference for traditional communication, (2) not being aware of the portal, (3) low technological proficiency, and (4) poor interoperability between the portal at the transplant center and the patient’s primary care center. Conclusions: We identified several modifiable barriers to patient portal use. Some barriers can be addressed by patient education and training on portal use, and federal initiatives are underway to improve interoperability; however, a preference for traditional communications represents the most prominent barrier. Additional strategies are needed to improve portal adoption by encouraging acceptance of technologies as a way of clinical communication.