Zotero and Endnote
If you have decided to use Zotero and you already have an Endnote library, it is easy to transfer your references from your Endnote library to your Zotero library.
Use the below instructions for transferring your references, or, transferring your references and the PDF's if you have PDF's in your library.
You can import your whole Endnote Library, a particular group, or selected references into Zotero.
The next step depends on whether you you have file attachments (e.g. PDF's) in your Endnote library or not. If you don't have file attachments follow the instructions for References only. If you do have file attachments, follow the instructions for References and File Attachments.
Transfer data between Endnote and Zotero
1. Open your Endnote library. From the Edit menu, choose the Select All option. This will highlight all of the references in your Endnote library. If you only want to send part of your Endnote library, just highlight the particular references that you want to transfer.
2. Next, click the File menu and select Export.
3. A pop-up box will appear. This is where you choose a name for the file you are exporting, a file type and a destination save it.
Save Location: can be anywhere you like, e.g. Desktop, My Documents, etc.
File name: Can be any name you choose.
Save As type: Text File (*.txt)
Output Style: click the Output Style drop-down menu, then Select Another Style. From the Style list scroll down to Refman (RIS) Export and click Choose.
RIS is a format common among reference management tools, and will allow your Endnote Library data to be read by Zotero.
Click Save to save this file to your Desktop
4. Open your Zotero library. Click on the File menu and then Import. In the pop-up window, choose the EndNote file you have on the Desktop. Your Endnote references will be imported into your Zotero library.
If you have file attachments such as PDF's in your Endnote library, you may want to transfer these to Zotero along with the references themselves.
To do this, you need to save your exported Endnote Library .txt file in a very specific location, before you import it into Zotero.
1. Open your Endnote library. From the Edit menu, choose the Select All option. This will highlight all of the references in your Endnote library. If you only want to send part of your Endnote library, just highlight the particular references that you want to transfer.
2. Next, click the File menu and select Export.
3. A pop-up box will appear. This is where you choose a name for the file you are exporting, a file type and a destination to save it.
You need to save your exported Endnote .txt file into the Endnote .data file of your existing Endnote library. This will allow Zotero to find the necessary PDF files to attach to the imported records. You will find your Endnote .data file in the same location that your Endnote library file is saved (.enl).
If you don't know where your Endnote files are saved, go to your Endnote library Tools menu and click Library Summary. This will tell you the location of your Endnote library files.
Your Endnote .Data file will now look like this:
4. Open your Zotero library. Click on the File menu and then Import. In the pop-up window, choose the txt file you have saved into your Endnote .data file. Your Endnote references will be imported into your Zotero library, including attachments.
To check that the PDF's/attachments have been imported along with your references, click the small arrow next to each reference 
in your Zotero library, this will show the attached PDF's, as in the below example.
