The literature about the treatment of giant cell arteritis (GCA) is diverse and often includes patients with polymyalgia rheumatica (PMR) who do not have concurrent features of GCA. Consequent heterogeneity has contributed to controversy in the analysis of clinical data. Nevertheless, we have critically reviewed this literature to derive a rational approach to initial and maintenance corticosteroid (CS) therapy and thus define "CS-resistant GCA." In this article, the authors review what has been written about the treatment of presumed CS-resistant disease. Although firm recommendations are lacking, the authors provide algorithms for the treatment of GCA patients who fail to respond to initial CS therapy or who require potentially toxic maintenance-dose CS therapy. A study design that may help to resolve the dilemmas that were found during our analysis is also outlined.