Command execution on files within the current directory and subdirectories

Could someone help me in achieving this? I need to able to execute a command on the files on the base directory as well as all the files in the subdirectories.
I was only able to do this for the files on the base directory but I'm not sure how to recurse through all the sub directories and execute the same command on the files in the sub directories.
I'd appreciate any help.
Thanks,
Srinivas