To measure the reported benefit in quality of life (QoL) and audiological performance in a group of 'non-traditional' patients undergoing cochlear implantation, and compare the results with those of patients satisfying established criteria for implantation.Longitudinal retrospective observational study.Ten consecutive early-deafened, late-implanted patients, here termed 'non-traditional' patients, with a mean age of 31.3 years (range 15-52 years) and implant experience from 8 to 76 months (mean 40.9 months).The Glasgow Benefit Inventory (GBI) was used to evaluate benefit in QoL. Auditory performance tests consisted of: (a) recognition of environmental sounds using the UCL/RNID lists; (b) speech pattern perception using the Three Alternative Forced Choice Test; (c) speech discrimination using modified CUNY sentences in two conditions: lip-reading alone and lip-reading with the implant. Lip-reading enhancement scores were extrapolated.GBI scores varied widely from 3 to 67, with a mean of 38.9, which is comparable to the mean score of 40 reported for 'traditional' candidates. Half the subjects were totally satisfied with their implant (scoring 100), and the mean satisfaction rating was 82.7. The mean scores obtained in environmental sound discrimination (40.5%) were a little below those of conventional, 'traditional' candidates, while those for speech pattern perception (73%) were within a comparable range. In contrast all ten subjects scored zero on open-set speech perception tests after implantation. The mean lip-reading enhancement score (7.6%) was significantly below that achieved by 'traditional' cochlear implant candidates.This group of 'non-traditional' adults demonstrates measured benefit in QoL, which is comparable to that achieved by 'traditional' candidates, but is not accompanied by a parallel improvement in performance on speech perception tasks. These results suggest that factors other than auditory performance may be equally important from the patient's perspective, and that some patients who might be considered poor candidates may still derive considerable benefit. It is suggested that benefit and performance be viewed as separate outcomes in this 'non-traditional' population.