If you only took 1 and have no previous history of opiates it will probably clear the next day. Contrary to the 3-5 day answers you will undoubtably receive, percocet contains oxycodone which is a short acting opiate. A lot has to do with your metabolism but. 10 mg is a small amount. If you were using them on a daily basis, at high doses (6-8 daily) it would take the 3-5 days everyone says. But 1 percocet will leave your system no longer than 24 hours and probably 12. I get my facts from physicians pain journal which I just spent the last as hours reading. I came up with clean urine after taking a 20mg opana&10mg perc. Now I know why. The person who answered me is mistaken, although - do appreciate him trying to help.