Correlation effects which arise during self‐diffusion are normally associated with a tracer‐defect mechanism. It is not widely appreciated that diffusive mechanisms, which are not normally considered to be correlated, may become so as a consequence of crystal contamination. Two examples are given to illustrate the establishment of diffusive correlations by solute element contamination. The examples are interstitial diffusion in a dilute fcc ternary alloy and vacancy migration in a dilute binary fcc alloy.