Objective: To describe the diagnostic management of patients with atherogenic dyslipidaemia (AD) by primary care physicians (PC). Methodology: An observational, descriptive, cross-sectional study was conducted based on a structured questionnaire. The content of the questionnaire was based on a review of the literature, and was validated by 3 AD experts. It included 23 questions, and was addressed to primary care physicians (PC). This sub-study will analyse questions related to the detection and diagnosis of AD. Results: A total of 1,029 PC participated in the study. Almost all (96.99%) said that DA is a determining factor for cardiovascular risk (CVR), even with LDL-C targets. Residual CVR was evaluated by 88.43% in their clinical practice, but only 27.89% in secondary prevention. Most of the PCs used LDL-c-non-HDL-c (55.49% vs 20.02%) in AD as a control objective, and 15.35% used TG, and 9.14% HDL-C. For the diagnosis of AD, 82.22% used TC, TG, HDL-C, and non-HDL-C. PC physicians used the TC / HDL-C atherogenic ratio (53.06%) and LDL-C / HDL-C ratio (49.56%), considering them useful / very useful (86.30% and 85.04%, respectively), with only 28.08% using the TG / HDL-C index, with 69.29% considering it useful / very useful. Conclusions: The PCs have a high level of knowledge of the guidelines. Underdiagnosis continues, with heterogeneity in determining objectives, and low use of the TG / HDL-C index to evaluate these patients. Greater awareness is needed for the detection and diagnosis of AD. (c) 2020 Sociedad Espanola de Medicos de Atencion Primaria (SEMERGEN). Published by Elsevier Espana, S.L.U. All rights reserved.