Perfect Medium Rare Prime Rib Roast

Total Time
1hr 35mins
Prep 5 mins
Cook 1 hr 30 mins

Simple, basic, how-to recipe. Meat thermometer required. Cook to internal temperature, not elapsed time. Time is approximate for a 5-pound roast. Any size roast will do, just cook to the correct internal temperature. Add 20 minutes for resting time.


  1. Preheat oven to 450°F.
  2. Pat the rib roast dry with a paper towel or napkin.
  3. Smear the cut ends of the roast with the butter. Place the roast (ribs down or fat side up) in roasting pan.
  4. Sear the rib roast for 15 minutes at 450°F, then turn the oven to 325°F for the rest of the cooking time. Every 1/2 hour, baste the cut ends of the roast with the fat accumulated in the roasting pan.
  5. Cook until rib roast reaches an internal temperature of 120°F Remove from oven, cover loosely with aluminum foil, and let sit approximately 20 minutes. The roast will continue to cook as it sits. Serve when the internal temperature reaches 130°F.
Most Helpful

This was great for Easter dinnner, I did add salt & pepper and onion and garlic powder. My 3 pound roast was cooke to 165° and came out medium in the middle and medium well in the ends. Thanks for posting CipherBabe. Made for PAC Spring 2010.

ElaineAnn April 05, 2010

Fantastic! Used with Roast Beef Slather on a little 2 lb sirloin roast. 15 minutes @450 degrees F then 20 minutes @325 degrees F yielded a perfect medium rare roast. Will keep this to use again & again. Thank you CipherBabe!

Buster's friend September 27, 2007

This is absolutely the Perfect prime rib recipe!!!!! I seasoned mine in my usual way for meats, then followed the directions to a T, and voila! Perfect medium rare prime rib!!! My first try too!! And I was so nervous about making it, lol, as I was making it for my hubby and me, and my sister and brother-in-law who were up from Tx last year. And they were QUITE impressed, BIG complement coming from them as they have eaten at a lot of very fancy restaurants from all over the world, and I am just a home cook in small town MO. I am going to make this for my hubby this Friday for Valentines Day!!! He will be pleasantly surprised :D This is truly a fail proof recipe!!! Thanks Cipherbabe!!! :)

Ang Higgy February 12, 2014