The discovery of mycophenolic acid (MPA) as a potent immunosuppressant, able to inhibit B- and T-cell proliferation by blocking production of guanosine nucleotides required for DNA synthesis, allowed its potential in the field of transplantation to be realized. Mycophenolate mofetil (MMF), an MPA prodrug, has been shown to be an effective immunosuppressant in transplant therapy. Clinical trials in renal, heart, and liver transplant recipients have demonstrated that, in combination with cyclosporine and steroids, MMF therapy can reduce the incidence and severity of acute rejection episodes and improve graft and patient survival as well as graft function. Although MMF is generally well tolerated, optimal therapy may be limited by associated side effects, in particular gastrointestinal (GI) toxicity, which may occur in over 40% of patients. Dose changes resulting from GI side effects may potentially lead to sub-therapeutic dosing and impaired clinical outcomes. An enteric-coated formulation delivering MPA - enteric-coated mycophenolate sodium (EC-MPS) has been developed to improve MPA-related upper GI adverse events. EC-MPS delays the release of MPA, consistent with a functional enteric-coating. Recent clinical trials have demonstrated that EC-MPS is as effective and safe as MMF in both de novo and maintenance renal transplant patients.