There is much evidence that many post-main sequence stars are losing mass, that the integrated mass loss is sufficient to affect their evolution and that epochs of substantial mass loss are normal for almost all stars. However, neither the precise timing, nor the mechanisms, nor the full consequences of this mass loss are yet well understood. Stellar pulsation may play a key role: it is closely associated with evolutionary phases where substantial mass loss occurs, and there are good physical reasons to expect pulsation to cause, or at least greatly to enhance, mass loss. Here we point out that there are many possible consequences, some not previously recognized, of pulsation-related mass loss for the evolutionary behaviour of post-main sequence stars. We advance the hypothesis that most mass loss of evolutionary significance is closely related to stellar pulsation.