Irrespective of ripeness, the percentage of coloured berries removed by a raspberry harvester increased with an increase in the vibration frequency of the shaker fingers. The percentage of green berries removed at a low frequency (5.0 Hz) was unaffected by berry weight, but at a higher frequency (11.7 Hz) it usually increased with increasing weight. The percentage of coloured berries removed with stalks decreased, and the percentage without stalks increased, with increasing ripeness until the berries were over-ripe. Once berries had become very over-ripe the percentage removed increased even further with cv. Malling Jewel but decreased with cv. Glen Isla. Increases in vibration frequency decreased the ratio of the proportion of ripe berries removed to the proportion of unripe berries removed. The results suggest that raspberry harvester performance would be improved by using a relatively low vibration frequency coupled with a short harvest interval.