Anthropogenic disturbances are a major concern for the welfare and conservation of wildlife. We recorded heart rate and body temperature of 20 free-living greylag geese in response to a major regularly re-occurring anthropogenic disturbance, New Year’s Eve fireworks. Heart rate and body temperature were significantly higher in the first and second hour of the new year, compared to the same hour on the 31st of December, the average during December and the average during January. Heart rate and body temperature was not significantly affected by sex or age. From 0200-0300 onwards, 1st of January heart rates did not significantly differ from the other periods, however body temperatures were significantly increased until 0300-0400. From 0400-0500, heart rate was not affected by any of the investigated factors, whereas body temperature was significantly increased on the 1st of January compared 31st of December and the December average but not compared to the January average. To conclude, our results show that New Year’s Eve fireworks cause a substantial physiological response, indicative of a stress response in greylag geese, which is costly in terms of energy expenditure.