Mycophenolate mofetil (MMF) is used for oral administration to prevent rejection in renal transplant recipients, and is rapidly converted into mycophenolic acid (MPA), the active metabolite, by hydrolysis in vivo . The area under the concentration–time curve ( AUC _0–12 h) of MPA is considered to be an effective pharmacokinetics parameter for predicting acute rejection. However, frequent blood sampling is required to calculate AUC _0–12 h, which imposes a burden on patients and providers. Therefore, we examined a limited sampling strategy (LSS) for estimation of MPA- AUC _0–12 h using only a trough level ( C ₀) and two points including C ₀ in Japanese living-related renal transplant recipients with concomitant extended-release tacrolimus (ER-TAC). The present study suggests that better estimation of MPA- AUC _0–12 h can be obtained by using two points including C ₀ as compared with only C ₀ regardless of transplant progress. Furthermore, blood collection points showing the highest estimation of MPA- AUC _0–12 h by adding to C ₀ were C ₄ at pre-transplantation (Tx) and 1 month post-Tx, and C ₆ at 3 months post-Tx. We conjecture that changes in renal function and serum albumin (Alb) accompanying transplant progress are aggravating factors in terms of estimation, because there was also a significant difference in the reciprocal of serum creatinine (1/Scr) and Alb between pre-Tx and post-Tx in this study. In conclusion, the present study provides useful information for effective and efficient monitoring of MPA levels in Japanese living-related renal transplant recipients.