The objective of this literature review was to compare all the known various fracture mechanics approaches for pipeline girth weld defects or discontinuities which have been proposed to see if fracture mechanics techniques can be applied to determine defect tolerance. Although the British and the U.S. National Bureau of Standards are@ and have done significant work on defect tolerance in welds@ it was felt that a more fundamental review of the subject would be beneficial. The main emphasis in this review was on the available fracture mechanics relationships for predicting critical flaw sizes in girth welds. A minor emphasis was placed on stress state@ weld properties@ and fatigue crack growth rates.