Eating and rumination behaviour in 22 cows with traumatic reticuloperitonitis was recorded after the start of treatment. Based on the results of clinical, ultrasonographic and radiographic examinations, the cows were divided into two groups: Group A consisted of 12 cows without an intramural or perforating foreign body and group B had 10 cows with an intramural or perforating foreign body. Cows of group A received amoxicillin, flunixin meglumine and a NaCl-glucose infusion, and cows of group B received the same treatment accompanied by foreign body removal via ruminotomy. All cows were fitted with a horse halter equipped with a pressure sensor integrated into the noseband, and eating and rumination activities were recorded continuously for 7 days. Additional 24-hour- recording periods occurred on days 14 and 30. Results obtained previously from 300 healthy cows were used for comparison. Median daily eating time in group A was 168 minutes (reference interval 211 to 319 min) on day 1 and increased to within the reference interval by day 3. Eating time on day 14 was 290 minutes and significantly longer than on day 1. Eating time was 294 minutes on day 30. Eating time in group B was comparable, and the patterns of normalisation for the number of chewing cycles related to eating, rumination time, the number of regurgitated cuds per day and the number of chewing cycles per cud were similar to that of group A: all variables were significantly reduced on day 1 and normalised within 3 to 5 days. The findings showed that eating and rumination are reduced in cows with traumatic reticuloperitonitis and that successful treatment results in rapid normalisation. Monitoring eating and rumination behaviour using a pressure sensor integrated into a halter allows objective clinical assessment of cows recovering from traumatic reticuloperitonitis.