I had that same problem with my daughter at 5 1/2 months. She is 7 months old now and still not sleeping through every night, but it is getting a little better. I asked the same question on this board, and got no real help. I tried everything they said, but it didn't work. A lot of people said to co-sleep so that I could get my rest, but I found myself unable to sleep with her next to me. One thing I did find was in a book called the Nursing Mother's Companion (if you are nursing). They said that babies this age are more aware, and wake up during the lulls in sleep cycles and want to cuddle and nurse. They say the only ways to really cure this is to stop breastfeeding or let them cry it out. I didn't believe in either. At her 6 month check up we asked the doctor what to do, and he said to try and let her fall asleep on her own during naptimes, and eventually this would transfer over to nighttime. However, all she did when we put her down was play for a really long time, wake up even more, then cry increasingly until we came and got her. I am not for the "cry it out" method, so I still get up. Bianca also has acid reflux, but I don't think this is why she is waking up. She slept just fine before she was diagnosed at 2 months, and continued to sleep well until 5 1/2 mos. Our own measures have made it so that she only wakes up once a night. I try to feed her as much as possible before bed. You have probably started feeding solids (however, I noticed this start as soon as I started feeding her solids but that just makes this all too complicated) so feed her dinner (try to feed her rice cereal and peas or green beans instead of more sugar filled fruits and vegetables before bed). Then if you are nursing try to nurse her as much as she wants, then feed her a small formula bottle. We give Bianca 3 oz a night, I still have plenty of milk, and she is still almost exclusively breastfed (plus you can stop giving her those gross vitamins). Sorry I couldn't be more helpful, but it is probably just a habit she needs to grow out of. She also could be teething...