I assume you mean CS3 and you can try, but I wouldn't count on it working.
it is working for me.
Congratulations, Jackie. There are some people who have had an early version (CS3, CS4) on their computer and upgraded to Yosemite, and it continues to work.
However, it's very touch and go, and if you have to newly install or reinstall, there are no guarantees, and no support.
i spoke too soon. indesign didn't recognize a tt font as installed and then crashed when i tried to print.
but not indd.
am trying a trial of cc this morning