No! Not without damaging the plants. People do it but it is not good for the plant. Learn proper pruning techniques.

Pruning is seldom needed except for removal of faded flowers, but if it is needed, branches may be trimmed immediately after flowering. There is little need for pruning azaleas and rhododendrons. If growth becomes excessive, reduce the size with light pruning. Azaleas sometimes branch poorly and form a loose, open shrub. Plant form can be improved by pinching out the soft, new shoots of vigorous-growing plants. It is best to prune within two weeks of when they stop blooming. This is to prevent removing next year's flower buds. Rhododendrons and azaleas may be pruned after the flowers have faded to induce new growth. Prune out dead, diseased or damaged branches, and in cases where plants have become scraggly, start cutting the oldest branches back to encourage growth in younger branches. Pruning in summer of fall is not recommended since it will remove the buds for next year's flowers.

With the larger leaved rhododendrons (elepidotes), you must prune just above growth joints. Each year as the plant starts to grow there is a visible point where the plant started growth. We call this point a growth joint. Prune just above this point, because that is where the dormant growth buds are located. Don't prune between joints, because there are no dormant growth buds in that area. However, with azaleas and the small leafed rhododendrons (lepidotes), you may prune anywhere along the stem, though you may not be able to see them, these plants have dormant growth buds nearly everywhere.

As a plant grows, some of the inside limbs will be shaded out and become weak and die. It is a good idea to remove these, plus other weak limbs that are on the ground or crossing over each other. This provides better air circulation and does not provide a place for insects and diseases to start. Check azaleas for wilting or dead branches in late summer that may be the result of fungal cankers. These branches should be pruned back to clean white wood that is not infected while the weather is dry to prevent the spread of diseases.

Azaleas: Evergreen azaleas can be sheared for hedges or borders. Unlike rhododendrons, evergreen azaleas can be sheared each year after flowering to create a dense rounded plant. This is done extensively and with great results by highly trained Japanese gardeners. Deciduous azaleas can be cut anywhere on the stem and they will branch from that point, though they should not be sheared as severely as evergreen azaleas. After pruning, spraying with a fungicide may prevent infection.

I had a funny feeling that shearing would be a no go, thank you very much for all the helpful info Rhodyman.

I've been working on arborizing one particularly huge rhody, it's coming along pretty good. There are 2 other rhodies that need trimming - essentially I'll be removing all the new growth and then some. Unfortunately, whereas the plants are so tall, it's going to be hit or miss at the cut line.

Thanks again for the info, much appreciated!