More CSS files = more initial requests to the server = slightly slower loading the first time a page with those linked CSS files is requested. If performance is absolutely critical to your site (i.e. you have too many other bottlenecks already), then I wouldn't use the multiple sheets. However, if you feel it will make you more organized to go into a CSS file and instantly know what's going on and performance is fine on the site right now, then keep the CSS files. Your time is probably far more expensive than the site's bandwidth anyway .