Oral isotretinoin can affect inflammation markers in patients with acne vulgaris. This study aims to examine the impact of isotretinoin treatment on inflammatory markers in patients diagnosed with acne vulgaris. Material and Methods: Fifty-five patients diagnosed with moderate or severe acne vulgaris according to the Global Acne Grading Scale were included in this study. Patients were evaluated at regular intervals (at 0, 2 nd , and 3 rd months) during the treatment period. Complete blood count [including mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), plateletcrit, platelet distribution width (PDW), platelet-to-lymphocyte ratio (PLR), red cell distribution width (RDW)], Systemic Immune-Inflammation Index (SII), Systemic Inflammation Response Index (SIRI), Aggregate Index of Systemic Inflammation (AISI), monocyte-high-density lipoprotein (HDL) ratio, monocyte-to-lymphocyte ratio (MLR), MPV/platelet ratio, and serum biochemistry panel were assessed during isotretinoin treatment. Additionally, the Acne Quality of Life Scale was used to assess patients' quality of life. Results: A significant increase in PLR and RDW levels was observed during isotretinoin treatment (p<0.05). However, SII, SIRI, AISI, monocyte/HDL ratio, NLR, PDW, MPV, sedimentation rate, and C-reactive protein levels did not show a significant change during isotretinoin treatment (p>0.05). Furthermore, this study demonstrated that oral isotretinoin treatment reduced the severity of acne and improved patients' quality of life. Conclusion: Isotretinoin may have inflammatory effects shown with PLR and RDW. However, other inflammatory markers did not show a significant change during isotretinoin treatment. Further comprehensive studies are needed to better understand the relationship between isotretinoin treatment and inflammatory markers.