Acne vulgaris is a multifactorial disorder characterized by seborrhea, microcomedones, comedones, papules, pustules, nodules and possibly scarring. The pathogenesis of acne is not completely understood. Recent studies reported the possible role of reactive oxygen spesies (ROS) especially lipid peroxides in mediating acne inflammation. Malondialdehyde (MDA) is one of the final products of the lipid peroxidation that commonly used as a lipid peroxidation marker. This study was conducted to evaluate the correlation between serum MDA levels and severity of acne on male patients. A total 60 patients with acne who attended in Polyclinic of Department of Dermatology and Venereology, Dr Sardjito General Hospital and met the inclusion and exclusion were involved in the study. The patients were then classified using combined acne severity classification method into three group as mild, modrate and severe acnes. Blood sample were then taken from all subjects and serum MDA levels were determined spectrophotometer. The mean serum MDA levels of severe acne group (1.85 ± 0.368 μmol/L) were significantly higher than that moderate acne group (0.79 ± 0.159 μmol/L) (p = 0.000) and that mild acne group (0.52 ± 0.239 μmol/L) (p = 0.000). Moreover, the mean MDA levels of moderate acne group were also significantly higher than that mild acne group (p = 0.002). Significantly positive correlation was observed between serum MDA levels and acne lesions total count (r = 0.714; p = 0.000). It can be concluded, there is positive relationship between serum MDA levels and severity of acne vulgaris on male patients. ABSTRAK Jerawat adalah penyakit multifaktor yang ditandai dengan seborea, mikrokomedo, komedo, papul, pustula, nodul dan kemungkinan jaringan parut. Patogenesis jerawat belum sepenuhnya diketahui. Penelitian terkini melaporkan kemungkinan peran reactive oxygen species (ROS) khususnya peroksidasi lemak dalam timbulnya inflamasi. Malondialdehid (MDA) adalah hasil akhir peroksidasi lemak yang umumnya digunakan sebagai penanda peroksidasi lemak. Penelitian ini dilakukan untuk mengkaji hubungan antara kadar MDA serum dengan tingkat keparahan jerawat pada pasien laki-laki. Total sebanyak 60 pasien dengan jerawat yang berkunjung ke Poliklinik Bagian Kulit dan Kelamin, RSUP Dr. Sardjito yang memenuhi kriteria inklusi dan eksklusi terlibat dalam penelitian. Pasien dikelompokkan dengan metode combined acne severity classification dalam tiga kelompok yaitu pasien dengan jerawat ringan, sedang dan berat. Sampel darah seluruh pasien diambil dan ditetapkan kadar MDA serumnya dengan spektrofotometer. Rerata kadar MDA serum pasien dengan jerawat berat (1,85 ± 0,368 μmol/L) lebih tinggi secara nyata dibandingan dengan pasien dengan jerawat sedang (0,79 ± 0.159 μmol/L) (p = 0,000) dan pasien dengan jerawat ringan (0,52 ± 0,239 μmol/L) (p=0,000).