Yarding delays add significantly to the time and cost required to obtain a given quantity of timber. In this study, they increased total yarding time by as much as 28 percent. As yarding system complexity increases, the frequency of delays can also be expected to increase. For one balloon yarding system in a clearcutting and for a running skyline in a partial cutting, the frequency of operating delays was positively correlated with yarding distance. Operating delays for cable systems occurred more frequently in partial cuttings than in clearcuttings. Delays on two helicopter operations were caused chiefly by refueling and were not influenced significantly by either yarding distance or silvicultural method.