The effectiveness of a new design of electric strained wire fence (CSL fence) for managing rabbits is currently being assessed in a two year trial. It is being compared with a commercially available electric netting fence (Flexinet fence) and also with farmers' normal control methods. The study is taking place on commercial farms in Cornwall, England, where the fences are being erected to protect fields of cauliflower. The amount of rabbit damage to individual plants in each field is being assessed and the numbers of rabbits feeding in these fields are being counted. Plant yields at harvest will also be used to determine effectiveness. Observations of rabbit behavior at the CSL fence are being conducted to identify potential design problems and to assess solutions to these problems. There was no difference between the effectiveness of the two fences during the first six months of the trial. Few plants were completely eaten by rabbits in the protected fields (CSL fence: 5±6%; Flexinet fence: 0%) but, by contrast, most were eaten at the control sites (82±17%). No more than a single rabbit was ever counted at night on the CSL- (0.7.±0.1 rabbits) or Flexinet- (0.5±0.2) protected sites but up to 20 (17.0±3.0) were counted on the control sites. The few rabbits which were observed crossing the CSL fence either jumped through or over it. The CSL fence design is proving to be extremely cost-effective and in this trial it would already have recouped its costs many times over if it had been used to protect the control fields. It will be further tested next year. The research was funded by the Horticultural Development Council.