Background: Increasingly observed in adulthood, adult female acne is considered a common chronic inflammatory disease of the pilosebaceous unit, presenting polymorphic lesions, risk of sequelae and negative impact on quality of life. This is a disease that may persist from adolescence (persistent acne) or manifest de novo in adulthood (late onset acne). Its etiology is multifactorial, and most of patients don’t have any abnormality in plasma androgen levels. Objectives: To investigate the prevalence and biological characteristics of acne in adult women, over 25 years, employees of a university in Sao Paulo, Brazil. Material and Methods: Project approved by Institutional Review Board. All participants signed online Consent Form and Authorization for Photography. This was a cross-sectional online study by using a questionnaire which was uploaded at the intranet of the university. It was sent and visualized by 2560 women employees, but just 241 filled the 59 questions. The data are presented in a descriptive way, in number and percentage. Results: We’ve received 9.4% of responses (241/2560); acne was reported by 94.2% (227/241) and 87.2% (198/227) were still suffering from acne. The real prevalence of acne in that population may be estimated in 7.7% (198/2560); 96% of patients reported inflammatory lesions; 58% on face; 68.7% persistent and 8.5% late onset acne. Regarding the severity, 48.5% were mild, 44.9% moderate and 6.6% severe. Familial history of acne was present in 79% of the patients with persistent acne and 81% late onset acne. Polycystic ovary syndrome was observed in 35% of women with persistent acne, 15% have already been treated or were under treatment; on the contrary 21% presented late onset acne and 64% were treated. Psychological impact was reported by 39% of women with persistent acne and 46% used antidepressants. On the other hand, 8% of women with late onset declared psychological disturbances and 30% were in use of antidepressants. Stress was reported by 51% of women with late onset acne. Additionally, 54% and 68% of women with persistent and late onset acne, respectively, reported sleep disturbances. Our study showed that 60% and 55% of women with persistent and late onset, respectively, consumed a diet featuring a high glycemic load, preferably including sweets. Results about the use of skin care during the treatment (persistent X late onset acne) were quite similar: regular use of sunscreen (50% X 58%); moisturizers (30% X 43%) and cleanser for oily skin (42% X 47%). In addition, 32% X 26% were submitted to chemical peeling; 55% X 41% used oral antibiotic, 28% X 26% combined oral contraceptive, 11% X 19% oral spironolactone, and 22% X 13% oral isotretinoin. Conclusions: The prevalence of acne among adult women employees at a university from Sao Paulo, Brazil is high, and the biological characteristic of the disease corroborates many previous studies. It is important to highlight the predominance of persistent acne, mild to moderate, inflammatory lesions, frequent report of ovary polycystic syndrome with low level of medical care and sleep disturbances. The excessive use of oral antibiotics instead of hormonal treatment point out the need of medical education for the management of this disease that causes important negative impact in women’s quality of life.