Temporal artery biopsy (TAB) is the diagnostic gold standard for giant cell arteritis (GCA). GCA is treated by high-dose corticosteroids. In cases of high clinical suspicion, steroids may be administrated despite negative TAB, making TAB clinically irrelevant. We assessed the role of TAB in clinical decision-making in patients with suspected GCA and to identify factors associated with clinically irrelevant TAB. Charts of patients who underwent TAB from 2005 to 2010 were reviewed for clinical parameters potentially associated with GCA and clinically irrelevant TAB. We studied 143 patients with 99 negative (69%), 34 positive (24%), and 10 undefined (7%) TABs. Eventually 26 patients (18% of the entire cohort and 26% of the patients with a negative TAB) received steroid treatment for GCA despite negative TAB. The start of steroid treatment before TAB was associated with clinically irrelevant TABs. If clinical suspicion of GCA is high, a TAB can be considered clinically irrelevant.