Invited to first round case interview at McKinsey. Tips and preparation strategy?

Hey! Congratulations.

The answer depends on whether you are experienced in casing or not.

If not, I’d try to push back your interviews so that you have a couple months to prepare, and focus initially on case fundamentals (structuring, data interp, math, creativity, synthesis). You can engage a coach to give you a solid curriculum to maximise your time. 

Also, do not neglect the PEI, which also requires some careful preparation and results in many candidates getting rejections, even with strong case performance.

If you’re experienced in casing, then your prep should be focused on eliminating any of your weaknesses.

It’s hard to give a more targeted plan without a little more context

Assuming you understand the basis, a few tactical tipcs

• Structuring: take an MBA casebook (Google if you don't know what this is) and do framework drills by reading a prompt, timing yourself for 2 mins, and reading the rest of the case -- go through at least one entire casebook; develop your own framework for the high-probability topics, so you have a less canned, off-the-shelf structure to fall back on
• Math: if mental math is a stumbling block, download an app or use tools like the one here on PrepLounge to get quick/sharp with numbers; YouTube has a ton of content on case math if you need more help
• Business judgement: read WSJ, Economics, and/or primers on key industries to learn the basics (if you need to) 

Highly recommend working with a coach to prepare more efficiently. We'd start with a baselining session to provide a more precise answer on what I recommend you prioritize between now and your interview date. 

Congrats on the McKinsey invite — that’s already a big milestone. 
 

Here’s how I’d recommend approaching prep at this stage (based on both my experience and what I’ve seen work for others):
 

1. Practice 

Both

 Case + Behavioral (Daily, Back to Back)
 

McKinsey interviews often combine case + personal experience (PEI) in the same session, sometimes even switching midway — so your prep should reflect that.
 

• Do at least one full mock case per day with someone you don’t know well — it trains you to perform under pressure and adapt fast.
• Don’t neglect PEI. McKinsey places real weight on your stories. Prepare 2–3 real, detailed examples (leadership, conflict, drive) and rehearse them aloud. They should feel natural, not memorized.
  
  2. Build Case “Muscle Memory”

This isn’t about memorizing frameworks — it’s about training your brain to:
 

• Ask sharp, hypothesis-driven questions
• Break down ambiguous problems with structure
• Stay calm under pressure (even when you don’t know the answer)
  The more reps you get in now, the more naturally you’ll behave in the interview — without sounding robotic.
   

 3. Be Ready for the Classic Questions
 

Brush up on
 

• “Why McKinsey?”
• “Why this office?”
• “Why consulting?”
  And tie them to your own journey — not generic answers. McKinsey values authenticity and clarity of motivation.
   

If you’d like help with focused prep — I coach candidates specifically for McKinsey (including real-case simulation, PEI story feedback, and communication coaching). Happy to support if you want to level up fast.

Good luck — you’re already on a strong path!

– Pallav

Congrats!

Actually, there's a lot to mention. 

To begin with, and assuming you have a tight timeline, try to get a baselining assessment either with a coach or with an experienced consultant. This should help you get a sense of what you are already strong at and where you struggle. You can then tailor your prep journey accordingly. This is a more 80/20 approach to the prep process rather than trying all the materials and just cramming as much as possible in the little time you have available. 

Best,
Cristian