I studied for just under four months. If I worked the day shift, I definitely could have shaved a month off, but I don't recover well from working nights, was in a crazy OT stretch, and I don't study at night. Thankfully I passed, and this is how I did it. It might have been a bit overboard, but oh well. I watched the Laura Gasparis review, attended Cammy House-Fancher's review, which was so helpful, and answered cover-to-cover of Laura G's question rational book and every question online at Pass CCRN. I would say that I saw approximately 50% of the questions or ones very similar on the test to what I had been studying. Thankfully this test is not multiple answers, so that makes it a bit easier than I thought. It's not rocket science but very thorough. I have heard of people who have passed it without studying, well good for them, but Mam/Sir, you are a freak.