Only if you have a waterproof vibrator. In every vibrator or sex toy generally you can find instructions of how and where you can use it.
In the waterproof vibrator there is a special mechanism that protects the motor, batteries and other parts inside.
What I need to know about Adult toy?

Information:

Can I use my vibrator in the shower?
How can I clean my sex toys?
Is there a vibratores for man?
Why should I use sex toys?
Do vibratores work only on batteries?