We studied the influence of paragliding flying activity on female chamois Rupicapra r. rupicapra behaviour and distribution in four areas in the Swiss Alps. We observed chamois as they were overflown by co-operative pilots on controlled routes. Female chamois fled at great distances (up to a maximum of 900 m) in all areas and sought refuge within forest cover after paragliders appeared. Escape distances were larger when paragliders appeared over the animals than when they appeared at about the same heights, and were shorter when chamois were closer to forest cover than when they were in open alpine meadows above the timberline. Colour of the paragliders, distance to rocks, and group size did not affect the reactions of the chamois. In areas with regular paragliding, chamois moved away from the air traffic and eventually disappeared into the forest, and did so earlier with increasing flying activity. The chamois stayed within forest cover longer with increased duration of paragliding off the normal flight path. In an area with only sporadic paragliding, chamois sought refuge within the forest for up to four hours after single paraglider fly-overs. In an area with no paragliding, chamois stayed in the pastures and rocks above the treeline all day. This study provides a basis for the development of control measures for paragliding in certain areas.