Pastoralism is pervasive and has a long history across the rangelands of Trans-Himalaya. Disturbance associated with pastoralism can influence the behaviour of wild animals; hence, it is important to better understand its effects on wild animal behaviour. We compared the activity budget of the Himalayan marmot (Marmota himalayana) between areas experiencing both high and low levels of pastoralism, in the Upper Mustang region in Nepal. Scan sampling was used to collect diurnal activity budget data on adult marmots, whereas 2 min focal observations were made on foraging marmots to assess vigilance during foraging. Contrary to our prediction, there was no significant difference between areas of high and low pastoralism in terms of foraging behaviour. However, the vigilance activity of marmots was significantly influenced by the extent of disturbances associated with pastoralism. Marmots scanned the surroundings more often while foraging and spent more time scanning in high pastoralism sites as compared to marmots in low pastoralism sites. Although we found no direct negative effects of pastoralism on foraging time, marmots shifted the time of day when they foraged. This study suggests that marmots adjust their vigilance behaviour according to the environmental conditions in which they occur. These findings have important implications for the conservation of marmots in the wake of increasing pastoral activities and consequent increases in human-wildlife conflict in Nepal.