Objectives: To assess the accuracy of clinical laboratories in Lima in the determination of glucose, cholesterol and triglycerides. Design: Descriptive. Location: Center for Research in Biochemistry and Nutrition, Faculty of Medicine, San Marcos University, and clinical laboratories participating in Lima. Materials: Serum samples from donors. Interventions: Prior informed consent, serum samples were sent in 4-6°C cold chain to 88 blind duplicate clinical laboratories sampled. Results were received via email and arithmetic mean, standard deviation (SD), coefficient of variation (CV) and standard deviation index (SDI) were obtained; accuracy was assessed using the validation of biological variability (BV). Main outcome measures: Glucose, cholesterol and triglycerides levels. Results: The majority (>75%) of laboratory results were within acceptable range; laboratories out of control ran...