Mycophenolic Acid (Mpa), The Active Metabolite Of Mycophenolate Mofetil (Mmf), Is Used In Combination With Cyclosporine And Oral Steroids To Prevent Acute Rejection Following Renal Allograft Transplantation. The Aim Of This Study Is To Investigate The Effect Of Time After Transplantation, Patient S Demographic Factors (Sex, Total Body Weight (Tbw), Age) And Mmf Dosage (By Body Weight) On Mpa Plasma Clearance In Early Post Transplant Period. Mpa Plasma Levels Of 19 Patients Were Determined By Validated Hplc Method At Steady State, Early After Transplantation, When Graft Function Was Normal (Creatinine Clearance> 70 Ml/Min). All Patients Received Fix Dose Of Mmf (1 G Twice Daily) In Combination With Cyclosporine And Steroids. Area Under The Time-Concentration Curve (Auc) And Mpa Plasma Clearance Were Measured For Each Patient. Both Auc From 0 To 12h And Predose Concentrations Increase Significantly With Time After Transplantation (P<0.05), While Mpa Plasma Clearance Decreases With Time (P=0.02). There Was Correlation Between Tbw And Auc (P=0.01,R²= -0.627) As Well As Tbw And Mpa Plasma Clearance(P=0.04,R²=0.555). Mpa Auc And Clearance Showed No Significant Differences According To Patient S Sex Or Age (P>0.05). Mmf Dosage (By Body Weight) Positively Correlates With Auc (P=0.01,R²=0.628) But There Was Negative Correlation Between Tbw And Mpa Plasma Clearance (P=0.02,R²= -0.604). Our Results Demonstrate That Total Body Weight, Time After Transplantation And Mmf Dosage (By Body Weight) Affect Mpa Pharmacokinetics. We Recommend That Mpa Pharmacokinetic Monitoring Is Necessary To Individualized Mmf Dosing During Early Post Transplant Period.