In recent years, tacrolimus has been gaining ground over cyclosporin as the primary immunosuppressant for kidney, liver and heart transplantation. Even with the modern microemulsion form of cyclosporin, tacrolimus appears to win on some clinical outcomes. The drawback of tacrolimus is that it is more expensive than its rival. However, a recent study in the UK, reported at the British Transplantation Society's annual meeting in Oxford, UK, at the end of March, suggests that in renal transplantation, tacrolimus is more cost effective than cyclosporin microemulsion over a 3-year period.