It's as safe as you make it... it features AES256 encryption for the seed/keys and/or the entire wallet file itself... but if you choose to use a password like "password" or "abc123" then all the encryption in the world won't help you.
Additionally, if you are a fan of downloading spyware/malware ridden apps/utilities and/or visiting "dodgy" websites... then any wallet will be bad.
![Tongue](https://bitcointalk.org/Smileys/default/tongue.gif)