Horton temporal arteritis, or gigantocellular arteritis, is a panarteritis involving the mid-size and large arteries, in particular the temporal surface artery. This pathology is normally found in the elderly, particularly females. It can be manifest with some typical symptoms (i.e. cephalea, fever, visual disorders even leading to blindness mandibular claudication, high ESR, moderate anemia), there may be aspecific, atypical signs (i.e. only cephalea and fever, or widespread myalgia and artralgia) or it may arise following a cerebro-vascular accident. Treatment of this form of arteritis is based on the use of high doses of corticosteroids over a long period of time (at least 1-2 years). The present work describes a surgical technique for biopsying the temporal artery. The technique consists of withdrawal of a segment of the artery from the main branch and the frontal branch of the temporal surface artery. Since this form of arteritis often presents segmentary lesions, it is advisable to take a 4-5 cm sample so as to prevent false negatives. This simple surgical procedure can be performed under local anesthesia and is practically complication-free. The authors then discuss the indications for temporal artery biopsy and report 3 clinical cases (case no. 1 is an example of the classical manifestation while cases no. 2 and 3 are atypical, aspecific forms). Since both the classical and atypical forms of gigantocellular arteritis require high doses of corticosteriods over a long period of time, the temporal artery biopsy procedure is highly useful in formulating an accurate diagnosis. The well known side effects to long-term cortisone use make it necessary to use all the available instruments in making the correct diagnosis. Bilateral biopsy can be performed in those cases where the first biopsy proved negative but gigantocellular arteritis is still suspected.