We all goof sometimes by accidentally deleting files we need. Here's how you can restore deleted files in Dropbox.
1. Go to the Dropbox site and sign in.
2. Click the recycle bin in the top right.
3. All files and folders deleted in the last 30 days will be displayed.
4. Right-click the file(s) you want to restore, and then choose Restore from the menu.
If you delete a file locally, it will be deleted remotely on Dropbox as well. That does not mean that the file itself is gone right away, as Dropbox maintains a copy of it in the recycle bin for 30 days before that happens.More at Ghacks
Additional resources for Dropbox