OBJECTIVE: Acanthosis nigricans (AN) is a commonly observed sign in the neck and axilla of obese children and is considered to be one of the risk factors for type 2 diabetes mellitus: in this paper, the relationship between AN and body mass index, insulin resistance, leptin, and PAI-1 in children with simple obesity was investigated. METHODS: Thirty-eight children with simple obesity, 17 of whom were positive for AN, had their height, weight, abdominal circumference, and hip circumference measured, along with blood insulin, leptin, fasting glucose, and plasminogen fibrinolytic acid activation inhibitor (PAI-1). RESULTS: There were significant differences in the relationship between obesity, abdominal circumference, fasting insulin values, and automatic dynamic equilibrium criteria to evaluate insulin resistance index (HOMA-R) in AN-positive individuals. there was no relationship between AN and body fat percentage. all of the AN-positive obese children showed very {values, PAI-1: 40ng/ml or more, and leptin 30ng/ml or more were AN-positive. Conclusion: Simple obese children, especially those with positive AN, should be followed up with special attention to observe the development and progression of type 2 diabetes and coronary artery disease.