A semiempirical and ab initio study of the possible isomers and conformers of both CF3NHC(O)H and CF3NC(H)OH as well as the barriers to interconversion between them was carried out. All possible geometries were fully optimized in Cs symmetry with the mopac and gaussian programs. Both the semiempirical and ab initio calculations reproduced the experimental ordering of energies, i.e. all isomers and conformers of the formamide were found to be more stable than those of the imime. In addition, transition states between the isomers were found and the barriers to isomerization based on these calculations are in good agreement with experimental data.