Following package directions, cook macaroni in a large kettle of boiling salted water until al dente.
Drain, rinse with cold water, and drain again.
Turn into a large bowl: Combine artichokes and their liquid, mushrooms, tomatoes, and olives.
Add mixture to cooked pasta and toss gently.
Cover and refrigerate for at least 4 hours or until next day.
Before serving, season with salt and pepper to taste.