Drop user did not reduce size of tablespace file I have a  development environment in which I frequently copy a certain schema.

When I'm done with the copy, I will use OracleEM to drop that user/schema.

My problem is that this does not seem to reclaim the space that the schema was occupying from my tablespace file.

I read doing an DROP SCHEMA .... CASCADE would do this, but the users are already deleted.

Now my entire drive is filled up.

How can I reclaim this space now?
I don't think there's much value in me copying what others have done so well in explaining in the past, so I'll just point you at a brilliant blog post: Reclaiming Unused Space in Datafiles.

Essentially you just need to do:

ALTER DATABASE DATAFILE '/path/to/datafile.dbf' RESIZE 111M;