Knowledgebase
How to hide "Availability: In Stock" and "Availability: Out of Stock" on product pages in Magento
By default, on product details pages in Magento there's a label Availability which, depending on whether the product is in stock or not, has a value of either In Stock or Out of Stock. If you want to remove the label and its value from being displayed on product view/details pages, you can do that with a simple modification to the styles.css file of your theme.
If your Magento is installed directly in the public_html folder on your hosting account and you use the default theme that comes prepackaged with the application, then the path to the file on your Magento hosting account will be public_html/skin/frontend/default/default/css/styles.css. In that file find the following code:
.product-view .product-shop .availability { font-size:11px; }
and inside the brackets put display:none;, so that the code looks like this:
.product-view .product-shop .availability { display:none; font-size:11px; }
You can modify the file from the Files section of the Pixie control panel. Another way to do it is to download the file on your local computer with an FTP client (e.g. FileZilla), edit it with a text editor (e.g. Notepad, Wordpad) and upload it back overwriting the old file.
After that clear the browser cache and refresh the frontend of your site to see the result.
Keep in mind that if a product is out of stock and it can't be backordered, the message Out of Stock will also be displayed on category/product list pages. The above modification will not hide it on product list pages; it only works for product details pages.