Can you post a picture? The other tomatoes you list are usually of the Regular Leaf form, and I am wondering if you are confusing the Potato Leaf form with leaf curl?

If not, we need more info, so....

To be able to suggest what might be wrong with your plant, it would be helpful to know more about the environment it is in. So, here are the "usual" questions:

Is the plant in the ground or in a container?

If in a container, what growing medium are you using? How large is the container? Is it self-watering or do you manually water it? Is the container in full sun, part sun or shade?

For both container plants and inground plants, it would be helpful to know these things as well: How often do you water? Have you checked the moisture of the growing medium or soil 3-5" below the surface? Is it dry, just right, or soggy? Are you feeding the plant? How often? What are the NPK values of any fertilizers you are using to feed it? What has the weather been like in your area?

If the plant is in the ground: Have you used any amendments? Do you mulch? If so, with what and how much (how deep)? Are there any other plants near the problem plant? Do they show the same signs?

The more information you can give us, the better the chances that someone can give you an accurate diagnosis.

Betsy

Betsy my cherokee purple is regular leafed and my red brandywines are potato leafed.they are in the ground and none of the other tomato plants are showing these signs,might just be those that I'm calling cherokee purple(cant guarantee my seed source because of trading)are more suseptible to environmental stresses because we did go near 100 degrees last week and thats when I noticed.other than that they are healthy and growing vigorously.Was just curious..

In our Oklahoma heat Cherokee Purple does great and the Brandywines do not, so I doubt it is a heat problem.

I have a very small garden and have a Cherokee Purple tomato in a container. About 2 weeks ago, I noticed the leaf curl. I was watering twice daily because of the extreme high heat. I thought I might be watering too much, so I have backed off to watering once a day and have moved the plant to an area where it gets some shade in the afternoon. What causes the leaf curl and what can I do about it. I don't want to lose the plant.

odd...I also have one variety with leaf curl this year...and this started with my second transplanting into a larger pot..before they went into the ground. It was on Aunt Ruby's German Green...I read that it could be psychological? or I guess we can translate that to stress? The one I have planted here is fine now, and I had given the other away...
other than that sometimes aphids get into the leaf and the leaf curls...good luck ;-> Martha/Zucchini