A study was undertaken of the precipitation in multi-pass 316L and 317L weldments in as-welded conditions. A feature of the work was that the microstructure of the welds was compared by trepanning 3 mm discs from specific positions. Specimens for transmission electron microscopy (TEM) were prepared from the discs. The volume percentages of delta(δ)-ferrite and intermetallics were determined by taking the mean of values obtained from 30–40 fields of view. Selected area electron diffraction (SAED) and energy dispersive X-ray analysis (EDAX) were used to identify the phases present in the various positions within each weld. In regions where overlapping of two welding passes occurred and hence where there was some remelting of the initial pass, the chi(χ) phase was identified. This precipitated usually at the delta/austenite phase boundary in the size range 0.05–0.1 μm probably due to the higher Mo and Cr, and lower N in these regions. The higher Mo content resulted in a higher volume % of χ phase in the overlapped pass region of the 317L welds compared to the 316L welds. One case was observed of sigma(σ) phase which was probably transformed from the χ phase.