Residual stresses due to welding have been estimated using a nine-noded degenerated shell element with assumed strains. It is well known that shell elements are capable of handling three-dimensional (3-D) configurations with less computational effort when compared to the full 3-D analysis. The temperature field in the entire weld domain has been calculated using a 3-D brick element. The temperature variation so obtained is utilised to find the distribution of the stress field using the concept of through-thickness integration. Thermal strains at individual Gauss points are calculated and the same are integrated to obtain the nodal loads. Thermo-elasto-plastic formulations using a von-Mises yield criterion with linear isotropic hardening has been employed. The formulations are validated with 2-D and 3-D experimental results available in the literature. It was established that this method can be used for estimating residual stresses in shell-like structures.