If you have been using Zotero previously you may have a library or a collection of references you want to export to EndNote. This is possible to do. If you want to you can also have attached PDFs included.

Export without attachements:

Open Zotero. Choose File, then Export library.
You will now see a menu on your screen. Here you choose RIS as format, and tick off that you want all notes, files and annotations to be included.
Click OK, and save the folder somewhere you can find it.
Open EndNote. Go to File, then Import, and choose File here as well.
You will now see another menu on your screen. Here you locate the file you have saved in the field Import File, choose Reference Manager (RIS) as Import Option and Unicode (UTF-8) as Text Translation.
In the field Duplicates you may choose Import All if you want all references into your library, but you can also choose Discard Duplicates if you want references that are already in your library in EndNote excluded from the import.
When you now click Import, all references are exported from Zotero to EndNote, without attachments.

Export with attachements:

This can be a bit more challenging, but it is possible:

Open Zotero. Choose File, then Export library.
You will now see a menu on your screen. Here you choose RIS as format, and tick off that you want all notes, files and annotations to be included.
Click OK, and save the folder somewhere you can find it.
Open EndNote. Go to File, then Import, and choose File here as well.
You will now see another menu on your screen. Here you locate the file you have saved. It will consist of two parts: A library file and a folder with PDFs.

Choose the library file, so it is inserted into the field Import File. EndNote generated XML is selected as Import Option.
In the field Duplicates you may choose Import All if you want all references into your library, but you can also choose Discard Duplicates if you want references that are already in your library in EndNote excluded from the import.
When you now click Import, all references are exported from Zotero to EndNote, without attachments.
To include attachments you have to do the process in EndNote once more, but this time you choose File, Import and then Folder. You then insert the folder PDF from your Zotero library as Import Folder. Tick off «Include files in subfolders» and «Create a Group Set for this import”. Import Option is PDF.
When you have done this EndNote should start syncronizing, and PDF should be attached to the references you have imported from Zotero.

If this doesn’t work and PDFs are not imported, it can help to copy the folder PDF you’re your Zotero library into the folder with data files in your EndNote library.

To do this you have to find the location on your computer where your EndNote library is saved, and put the folder PDF there together with the other data files in EndNote.

Picture showing the two parts of an EndNote library.

Open the data folder and copy the PDF-folder from Zotero into it. Then EndNote will syncronize, and PDFs will be attached to the library.