Normal urine is pale yellow or orange in colour. Greenish urine may be caused by a urinary tract infection or by the recent use of certain medications. If you have recently taken large amounts of cephalosporins, aminopterin, cimetidine, amitriptyline etc., this can cause your urine to turn green and will usually return to normal after you stop taking the drug. However, if the green urine is accompanied by symptoms such as frequent urination, urgency or fever, or if the urine remains green after stopping the medication in question, you should seek medical attention.