Render Not Showing all Layers?

I have a scene set up and it has a few layers, each with its own objects. In the program and the Pre-Viz, it shows all the layers I have selected. But as soon as I go to do a final render, only Layer #1 appears. I have checked that all layers are shown.
Is there an answer to this problem?

For starters, check in Outliner if Camera icons are active at objects which do not render in final.
Other than that file usually is easier to debug. part of it which does not work?