Leg of lamb roasting on a rack in a kamado grill
    Photo: Corvair Owner, CC BY-SA 2.0, via Wikimedia Commons (cropped)
    3 min read Planning Guide

    Leg of Lamb on the BBQ (Bone-In or Butterflied)

    Short answer

    Roast a bone-in leg with indirect heat at 325–350°F (165–175°C), about 18 minutes per lb, and pull it at 130°F (54°C) for medium-rare. A butterflied leg grills in about 25 minutes: sear both sides, then finish on the cool side.

    Quick guide

    Leg of lamb on the BBQ

    2 h 10 min Medium Serves 6–8
    Cut
    Doneness
    Pull at (medium-rare)54°C / 130°F

    You need

    • 1 leg of lamb, bone-in, 5 lb (2.3 kg)
    • 4–6 garlic cloves
    • A few sprigs of rosemary
    • Olive oil, salt, black pepper
    • Kitchen string (optional)

    1. Season

      Cut small slits all over and push in slivers of garlic and small rosemary sprigs. Rub with olive oil, salt and pepper — the night before if you can.

    2. Set up indirect heat

      Fire on one side, 165–175°C / 330–345°F on the other.

    3. Roast

      On the cool side, lid closed — about 1.5 h.

    4. Check

      Pull at 54°C / 130°F in the thickest part, not touching the bone.

    5. Rest and carve

      Rest 20 minutes tented with foil (it reaches about 57°C / 135°F). Carve against the grain, around the bone.

    Plan it around your serving time →

    Leg of lamb is a festive alternative to turkey or beef, and the grill suits it perfectly. Choose bone-in for a showpiece roast, or butterflied for speed and lots of crust.

    Bone-In or Butterflied?

    Bone-in looks spectacular and stays juicy, but needs 1½–2 hours of indirect heat. Butterflied (boned and opened flat) cooks in under half an hour and gets crust on every slice; ask the butcher to do it.

    Garlic and Rosemary

    The classic pairing works because lamb's rich flavour stands up to strong aromatics. Push slivers of garlic and small rosemary sprigs into slits all over the meat, ideally the night before.

    Want to skip the guesswork?

    Doneness

    Lamb is best pink. Pull at 130°F (54°C) for medium-rare or 140°F (60°C) for medium. The USDA minimum for whole cuts is 145°F (63°C) after a 3-minute rest, which medium reaches as it rests.

    Plan Your Lamb

    Answer a few quick questions and get a full step-by-step plan.

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    Frequently Asked Questions

    How long to cook a leg of lamb on the BBQ?

    A bone-in leg takes about 18 minutes per lb at 325–350°F with indirect heat (1½ hours for 5 lb). A butterflied leg takes about 25 minutes.

    What temperature is leg of lamb done?

    Pull at 130°F (54°C) for medium-rare or 140°F (60°C) for medium, then rest 10–20 minutes.

    How much leg of lamb per person?

    About ¾ lb (340 g) bone-in or ½ lb (225 g) boneless per person.

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