Game fences are widely used to mitigate human—wildlife conflict and, where fencing is deemed the right choice, appropriate design, alignment and maintenance are the keys to effectiveness. We studied the effectiveness of the Makgadikgadi Pans National Park game fence along the Boteti River in central Botswana, one of the highest human—wildlife conflict areas in the country, using a spoor survey method and counting holes made by transgressing animals. We investigated the fence's effectiveness in separating humans and wildlife, as evidenced by the fence transgression frequencies of different hole-digging and conflict species. Since the fence prevents access to long stretches of river along the national park boundary, fence transgressions for lions (Panthera leo), elephants (Loxodonta africana) and all the digging species were higher during the dry season when there was no surface water available in the park. Conversely, cattle (Bos taurus and Bos indicus) crossed the fence and moved into the park in high numbers during the rainy season, probably to access grazing. Wildlife damage to the fence was highest in the dry season and without the implementation of prompt and constant maintenance and repair, game fences such as the Boteti fence cannot be effective in alleviating human—wildlife conflict.