Yes. But it's better to use yum all the time. It's more safe, easier and without any dependancies problems ;)
Yum uses RPM for most of its handy-work. In the end, it doesnt matter if you install an rpm by hand or with the yum tool. Yum just makes things quicker and easier.
People usually dont get into real "dep hell" with RPM unless they "use the --force, Luke."