Background: Patients with chronic kidney disease on hemodialysis are considered a vulnerable group. Due to the hemodialysis process, they are subjected to blood transmitted infections like hepatitis B virus. Uremia alters their immune system, which alters the response to vaccination against hepatitis B virus. Objective: Detection of the relationship between interleukin-12 (IL-12) level and, the response to hepatitis B vaccine in chronic kidney disease patients on hemodialysis. Patients and methods: This study was conducted in Sayed Galal Hospital among 60 chronic kidney disease patients on regular hemodialysis, and 25 healthy workers in the dialysis unit as a control group. Both groups were vaccinated against hepatitis B virus using Energix vaccine with full 4 doses. All subjects were subjected to detailed history taking, full medical examination, and some laboratory investigations. Data obtained from these procedures were then analyzed using SPSS program. Results: Response to hepatitis B vaccine was higher among control group. Interleukin-12 level was also higher among the control. However, in both the case and control group, there was a positive association between the level of interleukin-12 and level of hepatitis B surface antibodies (HBsAb) denoting better response. Conclusion: high levels of interleukin-12 were positively associated with better response to hepatitis B vaccine in patients with chronic kidney disease on hemodialysis and can be used as a predictor of response to vaccination.