Background: Although acne vulgaris affects mainly adolescents, there is a significant portion of females suffering from acne at and above the age of 25. Hormones play an important role in the pathogenesis of acne and females are usually subjected to an imbalance of hormones that stimulates the sebaceous gland and triggers acne. Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in females and is commonly associated with dermatologic manifestation of hyperandrogenism such as hirsutism, acne vulgaris and androgenetic alopecia. Aim of the work: To compare the clinical features of facial acne in adolescent and adult females. In addition, this study aimed to investigate associated hormonal abnormalities and/or underlying PCOS in those patients.Materials and Methods: Forty female patients with facial acne were enrolled in this study. Twenty patients were below the age of 25 (adolescent group) and twenty patients were at and above the age of 25 (adult group). The patients were subjected to medical history, clinical examination, assessment of blood hormonal levels namely total testosterone, prolactin, FSH, LH, estrogen, progesterone using ECLIA technique and free testosterone using RIA technique together with ovarian U/S.Results: All face regions were affected in both adolescent and adult cases with acne, however, forehead and cheeks were significantly affected in adolescent when compared to adult cases. Total number of acne lesions was higher in adolescents than adults but this was statistically insignificant. Pustular acne morphology was significantly seen in adolescent compared to adult cases. Different abnormal blood hormonal levels were detected in 60% of total cases. Elevated levels of total testosterone, prolactin, progesterone and LH were detected in 12.5%, 17.5%, 17.5% and 20% of total cases respectively. Elevated total testosterone level was detected in 15% of adolescent cases compared to 10% in adult cases. Significant elevation of prolactin and LH levels were detected in 25% of adolescent cases compared to 10% and 15% in adult cases respectively. Significant elevation of progesterone level was detected in 30% of adult cases compared to 5% of adolescent cases. PCOS was detected in 30% of adolescent cases compared to 15% of adult cases. Conclusion: Different clinical features and hormonal abnormalities may exist between adolescent and adult females presenting with facial acne. PCOS has a more common prevalence with adolescent acne compared to adult acne. Proper detection of associated disorders may help in the proper selection of treatment for female patients presenting with acne.