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Materials and fabrication technologies for welded structures are continually evolving. The drives to reduce weight and cost, increase energy efficiency, improve performance and reduce the environmental footprint continue to provide challenges in the fatigue design and production of welded structures. In this paper, a brief overview of several research topics and recent technological developments related to fatigue assessment for welded structures have been given. Good progress is being made for quantifying weld geometric parameters and defect acceptance limits which can be correlated to fatigue performance. Definitions of "average" and "high" weld quality have recently been proposed. The relationship between IIW fatigue recommendations and ISO rules for weld quality have been clarified. New generations of high and ultra-high strength weldable steels are being developed for advanced fabricated structures. To take advantage of higher material strength, the design and production processes must be harmonized to consider more detailed assessment, carefully defined weld preparation, post weld treatments for critical welds, carefully defined WPS and inspection procedures, and fatigue testing for design verification. High frequency mechanical impact treatment technologies have been shown to be effective for improving the fatigue strength of welded structures. Research is progressing and future IIW guidelines will include these methods and improvement recommendations for high strength steels. Well-defined FE meshing rules have been proposed for use with the effective notch method for fatigue assessment. This is especially useful in the transition region between the line local mesh and coarser global mesh. A strain-based extension of the effective notch approach has also been successfully used for low cycle fatigue assessment. The peak stress method has grown out of the well-established notch stress intensity approach by using well-defined meshing rules. Multiaxial fatigue design rules have recently been incorporated into the IIW recommendations based on an elliptical ΔσΔτ interaction equation that includes special provisions for material, load proportionality and variable amplitude loading. Fracture mechanics based fatigue assessment has the potential to be highly accurate for very complex structures. Weight functions which can be applied for complex stress fields are very promising. Guidelines are being developed to ensure the consistency of LEFM as a means of assessing the fatigue strength of complex welded structures.