In this study the accuracy of several prediction equations for voluntary roughage intake was examined. Validity was based on automatically recorded feed intake data from 82 cows kept under different feeding strategies: 43 cows were freely given a basal diet and concentrates from an automatic feed dispenser; 39 were freely given a total mixed ration and a mineral/concentrate mix 1 kg/head daily. Prediction equations for roughage intake of Lindner et al. (1981) for first lactation and of Gruber et al. (1990) for all lactations show the lowest mean square error (4.39 and 7.12 kgsuperscript 2 DM) with an s.d.superscript 2 of +0.24 and -1.3 kgsuperscript 2 DM, respectively. More accurate results were achieved with equations for cows given a total mixed ration. Degree of precision for roughage intake and total intake predicted was not different. Some of the equations are useful for estimating average intake of the herd, but high deviations between actual and predicted roughage intake do not allow accurate predictions within a herd.