Thermodynamic coupling effects become important in such applications as injection of low molecular gases into boundary‐layer flows, ablative thermal protection processes, chemically reacting flows, and membrane transport processes which involve large gradients of temperature or concentrations. Thermodynamic couplings due to thermal diffusion, diffusion‐thermo andobaliamdiffusion effects in multicomponent compressible laminar boundary layers with nonequilibrium surface chemical reactions are analyzed and compared with other available analyses for simpler specific cases. A generalized mathematical description of the boundary conditions associated with surface reactions and thermodynamic coupling contributions to the various fluxes is also presented. The boundary conditions are transformed into total enthalpy‐concentration fields, and a new generalized Damkohler number for surface reactions is defined. The applicability of the present theory is demonstrated by new solutions to surface catalytic reactions with coupled heat and mass transfer at the stagnation region with and without blowing or suction. These results are then compared with Chung’s uncoupled solutions.