As long as you handle the introductions slowly and carefully, and as long as there is enough room in your house for each cat to have their own "space", plus enough food and water dishes and litter boxes, you shouldn't have any problems. We have 10 house cats, and other than the occasional hissy fit everyone gets along nicely. As each was adopted we started them off in a large bedroom for a couple of weeks, with the door closed. Then we slowly started allowing selected cats in to meet the newbies...starting with the calmest in the family. We've only had one real fight, and that happened while we were out of town; Someone bit our Missy and she developed a nasty infection. Our vet happens to also be a behavior specialist and we think we've determined who did the biting and why, and have taken steps to prevent any more issues. We have a fairly large house, so everyone has plenty of room to pick their spots. We keep out 10 food dishes, 3 large waterers, and have 5 litter boxes that I scoop out twice a day at least. YOu wouldn't know when you walked in the door that we even have cats; and a wonderful dog too! So, adopt your new furbabies and enjoy!