It is shown that the transport coefficients for an almost‐Lorentzian mixture(m&bgr;/m&agr; ≪ 1, n&bgr;/n&agr; < 1)can be computed as a perturbation to the coefficients for a true Lorentzian mixture, which are known exactly. This method of computation is found to be much more efficient than the usual Chapman‐Enskog method. Application to partially ionized gases is discussed.