In recent decades, dairy cows have increased in size due to breeding selection for higher milk yield. Despite this, the dimensions of milking-parlour stalls have never been adjusted, and are still based on past practical experience of milking-machine manufacturers and advisory institutions. Milking stalls that are too small could lead to impaired behaviour of the cows during milking, owing to a lack of comfort. The aim of this study was to examine the current space allowance of milking stalls on dairy farms and to assess the effect of space allowance on cow behaviour (rumination, latency in entering the milking stall, elimination and restlessness) during milking.