Can I use Wordpress theme on Drupal?

With a WordPress test site setup, view the source code and make a copy naming it index.html. Make a copy of the CSS file, name it style.css and place it in the same folder as the index.html file. Transfer images from the WP theme to a new 'images' folder, which is located in the same folder as index.html and style.css. You can just copy the whole 'images' folder over.

Straight CSS theme
- index.html
- style.css
- Images folder
-- Images folder/ images

Open up the index.html file in a text editor like Wordpad and change the path and name for the style.css to which this file should correspond.

example:

<link rel="stylesheet" href="style.css" type="text/css" media="screen" />

And change the paths for the images if necessary.

Also, open the style.css file in a text editor and change the paths for those images if necessary.

Now just open the index.html file in a browser and see the results. You may have to tweak a few things and strip out some extraneous code from the index.html file. At this point, you're just looking to have a "front" page that looks exactly like the frontpage of the theme itself.

After you have your straight CSS "frontpage" template working and validated -- you won't need to be concerned with subpages if they look exactly like the front -- make a copy of the entire theme folder and rename it - this is in preparation of converting it into a Drupal theme. Then you change the index.html file name to page.tpl.php and commence to incorporating Drupal code into it, which you will find in one of the free Drupal themes you have chosen to help you.

Note: you will find that there are CSS elements for nodes, comments and admin that most likely will not be included in your css file. You can copy and paste these from one of the free Drupal themes. Don't forget to check out the links I provided above; they should be a big help.

Oh, and the biggest pain I usually encounter is the tedious task of making sure all the CSS elements from the style.css file match all the CSS elements of the Drupal theme files used, ie. node.tpl.php, comment.tpl.php, etc.