You can import a PDF into SmartDraw to serve as a standalone image or a background layer. To import your PDF, click the Insert command on the Home tab and choose PDF.
Browse your computer for the PDF file you want to add and click OK from the Import PDF dialog box.
The PDF will be converted to an image and added to your document as a single object. You can add layers on top of your object to trace your PDF or to add new layers of objects.
You can also import your PDF as a unique background layer. Simply, check the Import as a Background Image box. Learn about that here.
This means that instead of being added to the existing layer, your PDF will live on its own specialized layer type. You can click and resize the PDF you imported, but you won't be able to add other objects or shapes to this background layer. This allows you to keep your PDF separate from the rest of your document.
If you want to trace objects or make edits on top of your imported PDF, you'll probably want to the PDF scale to match your document. Learn how to match the scale of your imported image with your document.