If the delete is CAUSING blocking (are you using sp_whoisactive to watch what is going on?), I would look at the following:

1) no index on what you are using for where clause and you are scanning instead of seeking

2) you are deleting lots of rows

3) you have a very slow tlog drive

4) you have foreign keys in play (that are quite possibly unindexed)

5) you have trigger(s) that are gumming up the works with their activity

6) you have a UDF involved

It would be MUCH easier for us to help you if we saw the table script, sproc code and actual execution plan. Statistics IO would be nice too.