This was a single-dose study to determine the time it takes for mometasone furoate nasal spray to go in effect, after a single dose of 2 sprays per nostril. Patients who are eligible were exposed to ragweed pollen for 3 hours on one or two occasions. Patients who experienced adequate symptoms during the pollen exposure phase came back for a Treatment Phase visit. During the Treatment Phase visit, patients were exposed to ragweed pollen for 2 hours and then received either mometasone or placebo nasal spray. Symptom evaluations began on the patients every hour for the next 11 hours.