CONTEXT: There is a lack of understanding of what is normal in terms of sex steroid levels in older women. OBJECTIVE: To determine whether sex steroid levels vary with age in and establish reference ranges for women >70 years of age. DESIGN AND SETTING: Cross-sectional, community-based study. PARTICIPANTS: Included 6392 women ≥70 years of age. MAIN OUTCOME MEASURES: Sex steroids measured by liquid chromatography-tandem mass spectrometry. A reference group, to establish sex steroid age-specific reference ranges, excluded women using systemic or topical sex steroid, antiandrogen or glucocorticoid therapy, or an antiglycemic agent. RESULTS: The reference group of 5326 women had a mean age of 75.1 (±4.2) years, range of 70 to 94.7 years. Median values (range) were 181.2 pmol/L (3.7 to 5768.9) for estrone (E1), 0.38 nmol/L (0.035 to 8.56) for testosterone (T), 2.60 nmol/L (0.07 to 46.85) for dehydroepiandrosterone (DHEA), and 41.6 nmol/L (2.4 to 176.6) for SHBG. Estradiol and DHT were below method sensitivity in 66.1% and 72.7% of the samples, respectively. Compared with women aged 70 to 74 years, women aged ≥85 years had higher median levels of E1 (11.7%, P = 0.01), T (11.3%, P = 0.02), and SHBG (22.7%, P < 0.001) and lower DHEA (30% less, P < 0.001). Women with overweight and obesity had higher E1 (P < 0.001) and T (P < 0.03) and lower SHBG (P < 0.001) than did women with normal body mass index. Smokers had 17.2% higher median T levels (P = 0.005). CONCLUSION: From the age of 70 years, T and E1 increase with age, despite a steady decline in DHEA. Whether E1 and T are biomarkers for longevity or contribute to healthy aging merits investigation.