OBJECTIVE To study if rheumatoid arthritis (RA) is influenced by age at menarche, number of pregnancies and reproductive life span. METHODS This was a cross-sectional and retrospective study of medical records of 247 RA patients. We collected data on menarche, menopause, number of pregnancies, autoantibodies, serositis, rheumatoid nodules, and functional index of Steinbrocker. Association studies were done using the Student t and Mann-Whitney tests and correlation was determined by the Pearsonand Spearman tests. The level of significance adopted was 5%. RESULTS The mean age at diagnosis of RA was 43.2±14.1 years, the median age at menarche was 13 years and the median number of pregnancies was 3. Rheumatoid factor was present in 63.9% of the patients, 20% had antinuclear factor, 8.8% rheumatoid nodules, 2.8% had pleural effusion, and 2.4% had pericarditis. The Steinbrocker functional index showed that 45.6% had a score of 1, 40.8% a score of 2, 3 score of 9.1, and 4.3% a score of 4. We found an inverse correlation between the number of pregnancies and age at onset of RA (p CONCLUSIONS A precocious menarche and brief reproductive life indicate a poor prognosis regarding pleurisy. A larger number of pregnancies and late menopause show a protective effect, delaying the onset of the disease.