Lyme disease is the most common vector-borne disease in the United States with over 20,000 cases reported yearly. A common and sometimes severe symptom of Lyme disease is Lyme arthritis, which has clinical and etiological similarities to rheumatoid arthritis. While risk factors for Lyme disease are established, there have been no studies exploring risk factors for Lyme arthritis. To assess this relationship a cross-sectional study was conducted, using data from confirmed cases of Lyme disease reported to the Massachusetts Department of Public Health (MDPH) from 2000 to 2006. Bivariate analyses and ANOVA tests were conducted to assess the relationship between age, sex and Lyme arthritis, as well as other symptoms of Lyme disease. Results showed that those in the lowest quartile of age were more likely to be diagnosed with Lyme arthritis alone than those in higher age quartiles (p <0.001). No significant difference was seen in the proportion of Lyme arthritis diagnosis between males and females (p = 0.61). By recognizing that younger patients with Lyme disease are more likely to be diagnosed with Lyme arthritis, measures may be taken to improve early identification and treatment of Lyme disease in this group. We recommend that a future prospective study be conducted to further elucidate the true relationships between age, sex, and Lyme arthritis.