A Coupled CFD - FE Analysis, referred as Conjugate Heat Transfer (CHT) Analysis or Fluid Structure Interaction (FSI), is very important for the processes that involves simultaneous energy exchange between solid and fluid domains. If we consider IC engines, Exhaust Manifold is one of the critical areas where above mentioned phenomenon takes place.In this paper, temperature distribution in solid parts of exhaust manifold is obtained through Computational Fluid Dynamics (CFD) analysis which uses Finite Volume Method (FVM) for solving Navier-stokes equation and energy equation. Whereas thermal stresses are predicted through FE analysis which is based on Finite Element Methods (FEM).It is obvious to validate CFD process before evaluating thermal stress. Therefore initially CFD results are compared with experimental results and found more than 88% correlation.Thereafter in FE analysis, temperature field from CFD is mapped to nodes of FE model and thermo-mechanical stresses are evaluated. While evaluating stresses, material nonlinearity, and property variation with temperature is taken into account.