The Flory-Huggins interaction parameters chi for 23 gases (He, Ne, Ar, Kr, Xe, H-2, N-2, O-2, N2O, CO2, CH4, C2H4, C2H6, C3H6, C3H8, 1,3-C4H6, four C4H8’s, n-C4H10, iSO-C4H10, and n-C5H12) in five rubbery polymers (1,2-polybutadiene (PB), poly(ethylene-co-vinyl acetate) (EVAc), polyethylene (PE), polypropylene (PP), and poly(dimethyl siloxane) (PDMS) were determined from either literature data on Henry’s law coefficient and partial molar volume or those on sorptive dilation for each polymer/gas system. Values of chi for the gases increased in the order of PDMS < PP approximate to PB < EVAc approximate to PE. Among the gases except He and H-2 whose chi values are not reliable, Ne and Xe have respectively the highest and the lowest values of chi for the polyolefins. The chi values of the hydrocarbons were compared together with previously reported chi values of n-alkanes C-3-C-10. The dependencies of chi upon concentration and temperature were discussed on the basis of the literature data.