Immunization against vaccine preventable diseases is an essential but mostly overlooked issue in oncology practice. We aimed to investigate the utilization of adult immunization recommendations and the perception of the patients with cancer receiving chemotherapy on immunization. A 15-item questionnaire about immunization in adults with cancer diagnosis was administered to patients with various cancers treated in daycare chemotherapy unit of Hacettepe University Cancer Institute. Total of 229 patients completed the survey. Fifty-four percent of patients were vaccinated at least once, most commonly against influenza and tetanus over 18 years old. Higher rate of participants was opposed to vaccination of patients with cancer diagnosis compared with those who were opposed to vaccination of healthy adults. Vaccination was never recommended in 93% of the participants. Only 9% of patients (n=21) were shot after cancer diagnosis. There was a strong association between doctor's advice and vaccination status. Twelve of 15 patients (80%) who were recommended to be vaccinated did so whereas only 9 of 214 remaining patients (4.2%) were vaccinated. Among those not vaccinated after diagnosis of cancer, most frequent reason was; not recommended by the doctor. Neither vaccination rates nor perceptions on adult immunization differed by age, gender, marital status, presence of co-morbidity or type of cancer. Among adult patients with cancer and receiving chemotherapy, immunization rates were found to be very low. Main reason was the lack of recommendation by the primary physician involved in the treatment, mostly oncologist. Awareness on this issue in physicians, particularly oncologists, may increase vaccination rates.