Oh boy do I know this question. Ativan is a short acting benzodiazapine (valium, xanax, klonopin, restoril, are all benzos.) Ativan doesn't stay in your system for very long- although it does stay in your system longer than xanax, which leaves your body pretty rapidly. I'd say about 24-48 hours depending on how much Ativan you are taking. DO NOT stop your Ativan all at once or you will experience a very unpleasant seizure. (it happened to me with xanax- I ran out of it, and didn't have any in my bloodstream for three days, and then had my first seizure at work.) Benzos are highly addictive and good for panic and anxiety disorders but respect this drug. Don't self medicate yourself or you will build up a tolerance. I am on klonopin now (for the past 14 years) because I am unable to get off of it. ( I went to rehab and detoxed but then relapsed because the symptoms of withdrawal were too hellish to explain) Be careful!