<p>I have a 5GB database and a 20GB transaction log (SQL Server 2005). Not sure why it is so large or what happened to make it that large, it used to be around 1/2 the size of the DB. DB grows about 1GB/month. </p>

<p>Are there any guidelines to how how big your transaction log should be relative to your database file size? </p>

<p>EDIT: I'm not saying my transaction log is huge (I know some DBAs would laugh at my weenie-sized DB), just in relation to the DB file I think it is huge.</p>

If you have a lot of transactional behavior, it's not uncommon at all. However, you probably should investigate means of making it smaller. There are quite a few options for this, but without knowing your recovery model, I could never presume to make a recommendation. Start with this
MSDN link
, this
knowledge base article
, then move from there. Carefully. :)