As a major health problem facing dairy farmers worldwide with substantial economic, production and welfare consequences, lameness has attracted much attention over the last two to three decades (Boelling, 1999). Lameness as a linear type trait is measured by locomotion scoring as there is a high genetic correlation between lameness and locomotion score. Studies have included locomotion (as a predictor of lameness) and have associated lameness with no effect, an increase and sometimes a decrease in milk production of cows. Several reasons have been given for these differences and the need still arises for estimates of the effect of lameness on milk yield in herds with current dairy management. The objective of this study was to quantify the effect of lameness on the daily milk yield (DMY) of dairy cows.