The aim of this study was to evaluate changes in nasal and oropharyngeal flora in patients with acne during treatments with tetracycline and isotretinoin. Swab specimens were taken from the right and left nasal cavities and oropharynx of 55 patients with acne and 20 healthy volunteers who were admitted to the dermatology department (Etlik Educational and Research Hospital, Ankara, Turkey) before the administration of treatment and in the third month of treatment. Study participants were divided into four groups as follows: patients with acne on topical treatment only, systemic isotretinoin, and systemic tetracycline, and the control group. Of 55 patients with acne, 18 were male and 37 were female. The mean age of the patients and the control group was 22.21 ± 4.22 and 21.95 ± 7.64, respectively. Staphylococcus aureus was isolated from the nasal flora of five patients, normal flora was suppressed in the oropharyngeal cultures of seven patients, and normal flora grew in the cultures of the other 20 patients who were on tetracycline treatment. On the other hand, normal flora grew in the nasal and oropharyngeal cultures of all the patients who were on isotretinoin treatment. Treatment options and follow-up procedures for acne vulgaris may lead to the development of bacterial resistance and damage to flora. In particular, systemic tetracycline treatment leads to changes in flora of the nose and throat in patients with acne with an increased carriage of S. aureus. Therefore, careful attention should be paid to the duration of tetracycline treatment in order to not increase the risk of disturbance of microbial flora.