I shop at both on a regular basis, so I think I can offer some reasonable commentary here. Caveat: the BJs commentary is specific to my local store (Portland, ME) which is a relatively small location on the scale of warehouse clubs and notably doesn't have a food court or pharmacy, so there may be aspects of the store experience that don't apply at a larger BJs. My local Costco (Scarborough, ME) is a fairly typical Costco location in terms of size and I occasionally shop at other Costcos so I think my commentary on that end ought to be more generalized. Key differences: BJs has more consistent inventory (but a smaller overall selection) - I've found that Costco turns over much more quickly and what is on the shelves is much more variable week-to-week. BJs has more items that they stock consistently and less limited time or temporary items. This is excluding seasonal items which are pretty similar in terms of turnaround at both places. Conversely, Costco tends to have more "limited time" deals or one-off items, and when Costco offers discounting it tends to be much deeper than what you'd get with coupons at BJs. At least at my local locations, Costco has a much broader selection of personal care and home improvement items. Their prices are also a lot lower on things like over-the-counter medicines (sometimes by as much as 30-40%, so if you buy a lot of OTC meds this is a major point of differentiation). Costco also has a better selection of electronics and appliances (my local BJs doesn't sell large appliances at all, though you can order them online). Conversely, our local BJs has a much better selection of office supplies, i.e. pens, file folders, label printers/labels, etc. BJs tends to have smaller but still bulk portions on certain items, so for individuals or couples, it can be easier to deal with BJs portions. Kirkland Signature quality tends to be pretty consistent, whereas I've found some Berkley Jensen stuff that was not all that great. Not a major point of differentiation, though, and some Berkely Jensen stuff is good to excellent. There are more options for store brand Kirkland Signature items, whereas there are a number of areas where BJs doesn't offer a store brand Berkley Jensen item. With respect to the butcher shop, I've found that I generally prefer the selection at Costco day-to-day, but BJs occasionally has some crazy-good deals. They also carry national brands like Perdue if you care about, whereas Costco is almost entirely their own brand/supplier for meat. Costco's prices are lower day-to-day, but BJs often has coupons in the app/website that push their prices below Costco. A good example I ran into recently was an 8-pack of Duracell 9V batteries was 19.99 at BJs and 18.99 at Costco - however there was a coupon in the BJs app that pushed the price down to 17.99. I'm sure this is region specific, but our local Costco has a much broader selection of wine and liquor than our local BJs. I haven't tried the Berkley Jensen brand liquor but the little bit of Kirkland Signature liquor I've had has been excellent value for money. BJs also accepts all credit cards, whereas Costco only accepts Visa. How much this matters depends on whether you normally pay with credit vs debit (or other methods) and whether you have non-Visa cards that re specifically rewarding for warehouse club purchases. The BJs app and website are somewhat better than Costco. They've had the ability to search inventory in your local club and to place orders for in-club pickup for years. Costco's ability to search local club inventory and prices is relatively new, and not quite as comprehensive, though it is improving. Costco generally prices ground shipping into online orders, and adjusts prices accordingly. BJs is less likely to have different prices in-store and online, but more likely to charge for shipping. At least at my local store, the shopping experience is generally more pleasant at BJs, but a lot of that is down to the fact that they aren't as busy. BJs also isn't as intense about checking memberships - they don't check at the door, so anybody can come in and look around (of course you do need to scan it at the register). The BJs checkout/front-end system is night and day better than Costco. Costco self-checkouts don't have hand scanners, so if you have a large item you either have to flag down the employee supervising the self-checkouts, or you have to awkwardly pass it in front of the barcode scanner mounted on the self-checkout itself. BJs has wireless hand scanners, and if you scan something with the hand scanner it doesn't need to go on the scale - it just prints an alert on the receipt for the checker at the exit. With a similar sized order, I'd guess I can frequently get out the door in less than half the time at BJs vs Costco. Overall I think it just depends on what you buy relative to what your local stores stock. If you're happy with Costco I wouldn't go out of my way to switch to BJs (or vice versa). However with that said, BJs doesn't check memberships at the door (or at least they don't at my local store), so it's pretty easy to go in and check prices/inventory before you commit.