Pretty much yes....
You may have to change a little jumper on the hard drive. this is because each cable you can connect a hard drive (or CD drive) to can support two devices, one is a master and one is a slave (don't take any notice of the names, it really doesn't matter which is which most the time)
So for example if you already have one drive on the cable that will be the master so you'd have to set the second drive to be the slave else it wont be recognised.
this is what the jumpers look like, you just pull it off and put it back over a different pair of pins
http://techpaul.files.wordpress.com/2007/12/ju mper.jpg
There is normally a little picture on the drive somewhere that says what pins to put the jumper across for each setting
something like this though (will be different for your drive)
http://bugclub.org/sig-tinkers.html