The purpose of this study is to examine the natural history of hay fever among former college students who were diagnosed with this disease either before or after their freshman year. The diagnosis of hay fever or seasonal allergic rhinitis was based on a history of watery, itchy eyes, rhinorrhea, and sneezing occurring for at least 2 consecutive years during the same seasonal period. A total of 738 former Brown University students (69% males and 31% females) who were evaluated and underwent skin testing during their freshman year completed a 23-year follow-up questionnaire inquiring of their history of allergies and asthma. The mean age of this group at the time of the follow-up study was 40 years. During the 23 years subsequent to the original study, 131 developed new hay fever in addition to the 175 who had hay fever as college freshman, totaling 306. At the time of the 23-year follow-up, improvement was noted by 84.8% (28/33) of those with hay fever onset 1-5 years, 63.6% (56/88) of those with onset 6-12 years, 55.6% (40/72) of those with onset 13-19 years, and 38.7% (41/106) of those with onset 20 years and older. Among those with an unknown age of onset, 42.9% (3/7) reported improvement of hay fever symptoms. The trend of increasing percentage of improvement with younger age of onset of hay fever is of statistical significance (p value of < 0.0001) using the chi-squared test for trend. A total of 54.9% (168/306) had noted improvement, of which 22.9% (70/306) reported being symptom free and 32.0% (98/306) reported being better but not symptom free. Of the remaining 45.1% (138/306), the hay fever was unchanged in 33.3% (102/306), worsened in 9.2% (28/306), and unknown in 2.6% (8/306). This study suggests that over a long period of time, hay fever symptoms will improve in the majority of individuals.