How to batch delete RAW files, but only if the matching JPG file doesn't exist?

You'd need to write a script to do that.

Hi Iwan,

There's no automatic way to do that but I can think of some ways I might do that. 

But first I have to ask: Why? Does that mean that all raw files are poor quality images by default? What happens if you have a raw file that is very precious to you, would you delete it anyway? Also, if you have the original raw image, you can very easily create a jpg so every image HAS a jpg. FWIW, I'm a big fan of raw/DNG images and a JPG is at the end of the line of image processing for me.

But, if this is a big need, here's how I'd do it. BTW, you don't say how many files there are, if there are thousands, this might not be enough but hundreds it might be viable.

First I'd move the Content Panel off to the right side location and the Preview Panel to the middle. (Actually that's where I usually have them.)

In the filter menu I'd set it to "Show Unrated Items only." (You'll see why in a moment.)

Now make the Content Panel two images wide. This lets you see the images side-by-side and if you see a raw image that doesn't have the matching jpg, I'd Option/Alt-delete key the image. Once you do that the rejected image will disapear from the list (becasue of the filter setting I did a moment ago).

Continue doing this until you've gone through all of your images.

Now go to the filter menu and select: "Show Rejected Items Only"

Now you can see and then delete all of your Rejected Items en mass. 

Let me know if this is a viable approach for you.