As a safe and healthy work requires continuous monitoring of the harvesting technologies, in this master's thesis we have determined the psychophysical workload of the operator during harvesting with Highlander special forestry machine. Heart rate was recorded during 10 working days in the Javornik area. Measurements were carried out after windthrow, and fir trees were dominating. The results have shown that average workload of the machine operator during the study did not exceed the permissible limits, since the heart rate during work was 81,7 bpm, the working heart rate 32,7 bpm and heart rate reserve 23 %. Workload is greater during operations carried out outside of the cabin, during operations associated with felling and skidding with help of a winch and during delays necessary for work organisation and maintenance of the machine. It was proved that the workload during workday is significantly increasing and that it is different between the individual days. Work difficulty during maintenance can be reduced through technological solutions, while other operations outside the cabin can even have a positive effect on reducing the monotony of work.