Zircaloy-4 (Zr-4) is a zirconium alloy that has been used extensively within the nuclear industry in both power generation and research reactors. The potential for welded reactor core components to undergo embrittlement during neutron irradiation is an important materials property issue to be considered throughout the service life of the reactor. Of particular interest is the performance of welded joints which depend on the properties of both the weld heat-affected zone (HAZ) and the parent metal. For this work Zr-4 HAZ was simulated using a Gleeble weld simulator to rapidly bring the material into the β-Zr zone at peak temperatures of 1200 and 1400°C. The small punch (SP) test was then used to investigate the variation in fracture behavior of these narrow zones of the weld and compare them with the parent metal. A finite element analysis (FEA) model of the SP test was developed which can be used to predict the deformation and fracture behavior of Zr-4 welds and is compared with the experimental data obtained.