3.5 Book of vile darkness?

[Ilmryn]

Is there a 3.5 version of the book of vile darkness?

[The Glyphstone]

Nope. Most of its material is compatible with 3.5 after only minor modifications, though.

[JoshuaZ]

Nope. Most of its material is compatible with 3.5 after only minor modifications, though.

What Glyphstone said. The main differences are some of damage reduction needs to be changed to number/magic. Also, some of the spells have mechanics that are slightly wonky. For example, there's a spell very similar to Spectral Hand but has as phrased hard to adjudicate mechanics (I don't have my copy of BoVD handy and I don't remember the spell name). A handful of other spells don't require any mechanical adaption or adjustment for 3.5 but are simply broken. Mind Rape is in practice extremely abusable if it doesn't have some restriction, such as an xp cost.

A more serious issue is that there are balance issues where the most obvious updating to 3.5 leaves things not fully balanced; some stuff is too weak and other stuff too strong. A lot of the PrCs are too weak, with the notable exception of the very strong Ur-Priest. However, the Ur-Priest was officially updated to 3.5 (in Complete Divine I think). Most of the other PrCs are too weak. The Demonologist for example requires heavy spellcasting to get into but then has its own spellcasting advancement which doesn't stack in any useful way. Many of the PrCs connected to specific demons and devils are very weak. If you are willing to use homebrew, there are a variety of completely 3.5 compliant variants of these PrCs floating around the homebrew boards here, some of which are balanced and good. This Demonologist version by Krimm is much more passable.

As long as I'm not off on this tangent about general issues, the rules for using body parts to increase spell power are much too weak, and the rules for sacrifices are much too easy given how one can pump up knowledge(religion). So if you are modifying things for a 3.5 it might make sense to fix those as well.