Background & Objective(s):Isotretinoin has a dramatic effect in treating acne vulgaris but it has numerous widespread adverse effects. The study aimed to investigate the association between isotretinoin and liver functions and cholesterol level among acne patients. Methods: A cross-sectional study was conducted in outpatient clinic of Dermatology Department of Alexandria Main University Hospital among 285 acne patients on isotretinoin for more than one month and less than 6 months with normal baseline serum liver enzymes and cholesterol laboratory investigations. An interview questionnaire was used to collect sociodemographic data, pattern of drug use, and laboratory investigations data following treatment with isotretinoin. Results: The mean age of patients was 20.84±3.4 years and 68.4% of them were females. Regarding pattern of using the drug, 36.8% of cases took 80 mg/day for 4-6 months. Almost 30% of cases had elevation in alanine aminotransferase (ALT) level, 23.2% had elevation in aspartate aminotransferase (AST) level and 21.1% of the cases had elevation in cholesterol level. There was a weak positive correlation between dose, duration of taking the drug and elevation in the liver enzymes and cholesterol level. Conclusion: There was a significant difference in level of liver enzymes and serum cholesterol level before and after using the drug. The dose and duration of taking the drug are factors affecting the elevation of serum liver enzymes and cholesterol level.