The aim of this study is to present the evaluation and monitoring of a clinical pathway for thyroidectomy 1 year after its implementation and after 4 years' follow up. We compare the results of an evaluation and monitoring indicators series before and after the establishment of the clinical pathway for thyroidectomy in the Surgery Department of Morales Meseguer Hospital, a general university hospital in Murcia, Spain. Implementation of the clinical pathway led to a reduction in length of hospital stay for all the surgery patients (4.8 +/- 2.1 and 3.6 +/- 1.9 days before and after pathway implementation, respectively; P < 0.001). Implementation of the clinical pathway led to a reduction in cost in all the operated patients (3357 +/- 966 and 2695 +/- 970 US$ before and after implementing the clinical pathway, respectively; P < 0.001). Evolution of the mean hospital cost according to year of study shows a reduction from 2000 (3400 +/- 1056 US$) to 2004 (2404 +/- 666 US$) with a slight increase during 2005 (2721 +/- 1335 US$) (P < 0.001). Implementation of the clinical pathway for thyroidectomy has successfully reduced clinical variation and therefore the length of hospital stay and mean cost of the process. In subsequent years, no such major improvements have been made with regard to hospital stay, although they are still clearly better than those before pathway implementation.