Research in the development of additive manufacturing process employing direct metal deposition for the fabrication of fully functional parts and tooling has generated significant interest in the recent years. Three-dimensional welding is being investigated as an additive manufacturing technique for the production of real metallic parts using gas metal arc welding (GMAW) principles. The temperature field distribution during weld based rapid prototyping induces complex thermal stress evolutions and plays a big role in residual stress distributions. The present work is to investigate the temperature field and thermal stress distributions in the multi-pass single-layer weld-deposition based additive manufacturing using twin wire welding. A three-dimensional finite element model with the temperature-dependent material properties and moving heat source is modelled for the same. A double ellipsoidal heat source model is applied to calculate the twin wire weldingβs temperature field is used. The filler metal deposition is taken into account by implementing the birth-and-death functionality for the finite elements. The temperature distribution pattern and magnitude is subsequently obtained. This result is then used for estimation of residual stress and distortion due to the twin wire welding