I assume that the exact error is like
Code:
wim@btd-techweb01:~$ mysqladmin create somedb
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user: 'wim@localhost' (Using password: NO)'
You're trying to set a password for the mysql root user. If that root user already has a password, you have to provide the existing password as well.