Unless these are last year's leaves then do not cut them back. You can dead head if you choose, we don't, but you won't get any more flowers this year.

Late in the year the leaves will probably get black patches on them. When this happens you can cut them off.

I've been told to cut the leaves off as soon as they begin to look a bit tatty - so I have!

Hellebores are evergreen, so best to keep as much of the foliage as possible, for interest in the winter months. I cut off only the old, tattiest leaves and those which develop leaf spot. I leave the flowers stems until they die completely, as I want my hellebores to seed (which they do prolifically!).

Thanks everyone.

Removing the leaves early means that the Hellebore can't photosynthesis as well as it might like to. Our garden is too big to be pernickety about each plant/shrub/tree, I guess if you have a small town garden or like the manicured look it is different.