We have ours under the small sink in both houses. That's where my mom has hers as well.

Mine is under the small sink and I'm perfectly happy with it.

I've alway wondered what the function was of the big/small sink? After 30 years with a split sink, I now have a single... oh my, what I have missed for all those years!

I thought the small sink was for the disposal?

I've always had split sinks and found them to be awkward with larger pans, etc. Now I'm looking at a split sink with a low divide - a Kohler at Costco - I'm looking forward to it. If I were doing a disposal (we have a septic, so I'm not), I wouldn't have to decide which side it should go under. :-)

Mine is under the large sink and I don't like it that way. If you have a sink full of dishes and need to put something in the disposal it goes all over the dishes. After my independence day flood, however, I intend to put much less down the disposal. Wipe then rinse is my new motto.

I like the disposal in the smaller bowl. I often have something soaking, draining or just occupying the larger bowl while I am doing prep or cleanup work. With the garbage dispolsal under the small sink, I dont have to worry about items in the large sink being in the way of using the garbage disposal.
I also have a cutting board which I put over the larger bowl and it is so easy to slide cutting and scraps right into the smaller and down into the disposal

Small sink here. I use the smaller side for prep and the larger side for dishes (mainly pots and pans which I usually handwash). Wouldn't want the disposal in the large side as it would be useless when the sink was filled with soapy water, and awkward regardless since it's not on the prep side for me.

So it just depends on how you use your sink. Think about your usual routine to get the answer that will work best for you.

I am putting them under both. I figure with the prep sink I will have fruit and vegetable scraps to dispose of, and in the big sink I'll have plate scrapings.

We've always had ours under the big sink, but I tend to use the smaller sink to dry dishes so that configuration works for us. We did the same on our new sink and I'm still happy with it.

I have always put it under the small sink but in our latest reno, I had it moved to the bigger sink. Like rkb21, we had begun to use the smaller sink to dry. I really like the change to the big sink.

That said, I lost a bit more undercounter space. The big sink was deeper, so the disposal hangs down lower. Another thing that cost space was the placement of the sink drain in the big sink. It was in the center. A sink that drains toward the back, as some do, moves the disposal closer to the back wall of the sink cabinet.

I was thinking about this recently when someone asked where I was going to put it but I ended up keeping with my initial plan to put it in the small sink for several reasons.
My reasons were:

1. I plan to use the small one for prep and the large one for dishes, that way I can use the disposal with dishes in the sink.

2. I'll have less of a chance of losing silverware down the disposal if I raise kids here one day (and honestly I need all the help I can get to keep from doing this myself).

3. It will move the bulky disposal to the side and give me more room under the sink.

4. It is the way it was done in my house growing up so it just seems more natural.

I know my reasons might be different than others but I just thought I would let you know what helped me to decide.
-Stuart-

Depends on how you use your sink. I prep to the left of the large sink and wash in that one so that's where the disposal is. I use the small sink with a rack in it to place the clean dishes as I wash and don't have a disposal there.

We put ours under the large sink, simply because it's on the left side, which was the same side the disposal was on prior to the remodel. I didn't think my husband would remember which side it was on if I switched it. It's worked out fine for us.