I've had the same experience as Patti, after four years of Arimidex. I've gained weight in my tummy area - the good news, though, is that I'm alive and well. A little extra weight seems a small price to pay.
Yes I have gained weight while taking arimidex. However, I can't say for sure that Arimidex is the cause. While recovering from surgery and taking chemo I wasn't able to exercise as much as I was. Also had a hysterectomy and early menopause. I am trying to increase my activities.