Background: This case-controlled study measured the measles antibody titer in children who survived cancer after chemotherapy to determine the patient’s immune status against the measles vaccine. Methods: We enrolled 38 children who were in complete remission and whose treatments had been stopped for at least 3months and 38 age and sex-matched healthy controls. We analyzed the medical records of the cancer survivors, and each study participant’s serum sample was analyzed by the ELISA method to determine the antibody titer against measles. Results: The cancer survivors had significantly lower measles antibody titers than the healthy control participants, and 78.9% of cancer survivors were unprotected (seronegative) compared to 7.9% in healthy controls. After multivariate analysis, there was no statistically significant factor associated with loss of protective humoral immunity against measles. Conclusions: These results underline the need for post-chemotherapy measles antibody testing and revaccination of seronegative survivors.