A study of the post‐construction crest settlements and deflections of 68 rockfill dams has been made in order to assess the usefulness and accuracy of the prediction of such deformations using empirical equations. Graphs of deformation per unit height against time are plotted for membrane‐faced (dumped and compacted rockfill), sloping, and central core dams. Comparisons of predicted and observed movements show that use of empirical equations can lead to large errors. An alternative approach is proposed, using only the deformation curves of existing dams with similar characteristics to the dam under consideration. Details are given in tabular form for each of the dams in the survey, as an aid to this approach.