We use Bayesian estimation techniques to assess whether money growth Granger causes inflation in the USA. We investigate the issue of Granger-causality out-of-sample and find that including money growth in simple VAR models of inflation does systematically improve out-of-sample forecasting accuracy. This holds for a long forecasting sample 1960–2005, as well for more recent subperiods, including the Volcker and Greenspan eras. However, the contribution of money to inflation forecasting accuracy is quantitatively limited and tends to be close to negligible in recent subperiods.