The experimental study has been done to investigate the through thickness residual stress variation in P91/SS304H welds joint. The gas tungsten arc welding (GTAW) has been performed for joining of the dissimilar metal using the Ni-based ERNiCrMo-3 filler. The residual stress measurement was performed in the weld metal, SS304H HAZ and P92 HAZ. The results showed a considerable deviation in residual stresses along the thickness and in the transverse direction of the weldments. The PWHT showed a significant effect on magnitude and nature of the transverse and longitudinal residual stress for both weld metal and HAZ. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.