Presented in this report are the results of three dimensional finite element analyses of a 45 degree photoelastic lateral pipe/vessel connection, subjected to internal pressure loading.Details of finite element modeling and analyses are described.Comparison of finite element peak stresses with photoelastic results, available in the literature, shows that the maximum deviation is twenty percent, with the photoelastic results being larger than the finite element results.However, the deviation is found to be less than 10% when the finite element calculations are carried out for a Poissons ratio value of 0.3 instead of 0.485 applicable to the photoelastic model material.