Hi there! I cannot eat OATS. Can I substitute plain white flour in a recipe that calls for oats? What's the ratio?

Also, oats have more texture (fiber) and nutty taste than does white flour.
If you can tolerate other whole grains you might want to consider one of them (ground, flakes or various formats).
As Antonia said, depends on what you're making.

What is the recipe? The two are not usually interchangeable. ;o)