The Canadian Quality Assurance Program was initiated in June 1989, and is a voluntary program which currently encompasses all 32 laboratories involved in the measurement of cyclosporine (CsA) across Canada. Two whole blood samples from control or clinical patients (kidney, liver and heart) containing unknown concentrations of CsA are circulated to each participating laboratory monthly, and analyzed by all techniques employed within that laboratory. Four analytical methods are currently employed: HPLC (n = 4). Sandimmun SP (n = 3), CycloTrac SP (n = 27) and TDx (n = 3). Four laboratories reported survey results in more than one methodology. Results from all participating centers are analyzed monthly. The mean, SD, standard deviation index and range are reported to each laboratory with information coded to preserve confidentiality. Accuracy, precision, recovery, analytical specificity, linearity and blank studies have been performed. This report covers the period from June 1989 to April 1990.