The effect of different NaCl contents in the rations for dairy cows on salt lick block (99% NaCl) intake was studied and the intake of 5 different commercial blocks was evaluated. After mixing, the ration containing 60% roughage (whole crop silage and grass silage) and 40% concentrates (maize ear ground, soya bean meal and compound feed) was offered, to two groups each of 32 cows. The only difference in rations between the two groups was that either no NaCl (low salt:LS) or 0.8% NaCl (high salt:HS) was added to the compound feed resulting in Na -contents in the rations of 1.0 and 1.7 g per kg dry matter, respectively. Five commercial hardened salt blocks were offered under the same conditions to both groups. Cows on LS consumed significantly more from the lick blocks than cows on HS (34 versus 24 g per cow per day) whereas no differences in DM-intake and milk yield were observed. This suggests a nutritional need for NaCl when dairy cows were fed rations containing from just enough (1.0 g/kg DM) to an adequate (1.7 g/kg DM) supply of Na . Significant differences in lick block intake were observed between blocks related to hardness and/or palatability. Although nearly all the cows used the lick blocks, block intake varied highly between cows from both groups from nearly 0 to max. 70 g per cow per day.