The majority of patients with cancer tend to seek health-related information via the Internet. This descriptive and cross-sectional study aims to determine e-health literacy, cyberchondria levels, and affecting factors in patients with cancer. The population of the study consisted of 113 patients who were older than 18 years, with no sensory loss that could hinder their communication, literate in Turkish language, who were conscious, actively used the Internet, and visited a university hospital's oncology and hematology polyclinic. In the multiple regression analysis examining the E-Health Literacy Scale total score according to sociodemographic and other characteristics, it was found that solitary complementary and alternative medicine explained 40.8% of the variance in the E-Health Literacy Scale score (adjusted R-2 = 0.408, P < .001). Additionally, it was determined that medication use without a doctor's recommendation and the duration of daily Internet use together explained 22.3% of the variance in the score on the Cyberchondria Scale (adjusted R-2 = 0.223, P < .001). Patients with cancer who develop better health literacy skills will be better equipped to navigate healthcare systems and alleviate their health-related worries.