Currently JIRA only supports deletion of projects one after another. Occasionally one needs to bulk-delete projects. Perhaps, on the JIRA Administration side, when viewing the list of projects. there is a checkbox and a delete button to bulk delete.

In instances where there are thousands of projects, some housekeeping or maintenance activity on the JIRA instance may require deleting projects that are no longer required. Some admins may need to delete 100s of projects at once.