INTRODUCTION: Eating and rumination activities were investigated in 100 cows from 14 days prepartum to 30 days postpartum. All cows were clinically healthy at the start of the study. A pressure sensor incorporated into the noseband of a halter was used to record jaw movements, which allowed the quantification of the daily duration of eating and rumination, number of regurgitated cuds and number of chewing cycles per cud. The cows were retrospectively divided into 2 main groups healthy (n = 24) and ill cows (n = 76), and the latter were further divided into the following subgroups: cows with periparturient paresis (n = 12), retained placenta (n = 13), metritis (n = 17), primary ketosis (n = 19) and lameness (n = 6). Healthy cows had the shortest eating and rumination times on the day of calving; duration of eating decreased continually before and increased steadily after calving. In contrast, duration of rumination varied little except for a significant drop on the days of calving. Compared with healthy cows, eating times of ill cows were significantly shorter before and after calving and rumination time was reduced on days 2 to 4 postpartum. The duration of eating differed between healthy and ill cows before calving, and therefore the usefulness of eating and rumination variables for early recognition of periparturient diseases in cows requires further investigation.