In this paper, the influence of the flaw shapes on the variation of stress-intensity factors along the crack front is examined for longitudinal inner surface flaws in pressure vessels, and for corner cracks present at the intersection of pressure vessel and nozzle. For the inner surface flaw problems, the geometry of the pressure vessel considered is that of the commercial pressure vessels and the analyzed flaw shapes and those recommended by ASME Boiler and Pressure Vessel Code. In the case of corner cracks at nozzlel-pressure vessel junction, natural flaw shapes obtained through experiments are considered. A fully three-dimensional linear elastic hybrid displacement finite element procedure was used to analyze these problems of practical interest in pressure vessel analysis and design. The obtained solutions are compared with those in literature using other numerical and/or experimental procedures, and a discussion of noted discrepancies is presented.