In the clinical practice of organ transplantation everolimus (RAD) is used in combination with cyclosporine (CsA), the most common antirejection agent. Both drugs show a narrow therapeutic window, which requires strict monitoring of their blood concentration. Simple methods for simultaneous measurement of RAD and CsA concentration are needed. As we have recently developed an HPLC-UV assay for RAD determination, we decided to implement it to allow concomitant measurement of CsA. The within- and between-day coefficients of variation of the measurement were less than 12.1% for RAD and 9.8% for CsA. The within- and between-day inaccuracy of quality control samples were less than 9.7% for RAD and less than 4.9% for CsA. The method was found accurate and precise and useful for simultaneous therapeutic monitoring of the two drugs.