The influence of an acrylic spray on claw soundness and the hardness of the claw horn was tested in 48 dairy cows kept in tied stalls the year round, After claw trimming D-Shore hardness as well as the health status of the claws was measured using the scoring system according to Brandejsky et al. (1991). On the right hand claws of front and hind limbs the spray was applied, the left hand claws were used as a control group. 8, 16 and 24 weeks after the application Shore-D-hardness was measured, A second scoring was performed after 24 weeks during the next routine claw trimming. Shore-D-hardness was equal in the treated and in the untreated group at each follow up examination. Claw soundness expressed in score-figures also showed no differences. Shore-D-hardness was significantly higher in the claws of the front limbs. Breed differences could not be observed.