Resumen Español Antecedentes y objetivo: La enfermedad cardiovascular es la principal causa de muerte en nin˜ os con enfermedad renal crónica. La inflamación y la disfunción endotelial se presenta en la mayoría de estos pacientes y son factores asociados a enfermedad cardiovascular. La dilatación mediada por flujo (DMF) < 7% es un marcador subrogado validado en la evaluación de la disfunción endotelial. Nuestro objetivo fue identificar los factores de riesgo asociados a disfunción endotelial en nin˜ os con enfermedad renal crónica. Materiales y métodos: Se estudió a nin˜ os de 2-16 an˜ os de edad. Se recopiló su información clínica y variables bioquímicas, incluidos hormona paratiroidea intacta (iPTH), interleucinas 6 y 1, proteína C reactiva de alta sensibilidad (hsCRP), glutatión reducido, óxido nítrico, malondialdehído y homocisteína. Se consideró DMF alterada < 7%. Resultados: Se incluyó a 129 pacientes con edad de 13,1 ± 2,6 an˜ os. Tuvieron DMF < 7% 69 (52,7%). Los pacientes con DMF < 7% tuvieron niveles más altos de triglicéridos y de hsCRP que aquellos con DMF ≥ 7% (145,5 vs. 120,0 mg/dl, p = 0,042, y 1,24 vs. 0,55 U/l, p = 0,007, respectivamente), así como una mayor frecuencia de iPTH baja (19,1 vs. 4,9%, p = 0,036). Los niveles de hsCRP se correlacionaron significativamente con la DMF (Rho = −0,28, p = 0,003). Los pacientes con iPTH baja (OR 4,41, IC 95% 1,13-17,27, p = 0,033) y con hsCRP incrementada (OR 2,89, IC 95% 1,16-7,17, p = 0,022) tuvieron un riesgo ajustado mayor de DMF < 7%. Conclusiones: La hipertrigliceridemia, la inflamación y una iPTH baja se asociaron significativamente a una DMF alterada. Son factores de riesgo de enfermedad cardiovascular frecuentes y tratables. English Background and objective: Cardiovascular disease is the main cause of death in children with chronic kidney disease. Inflammation and endothelial dysfunction are found in the majority of these patients and are factors associated to cardiovascular disease. Flow mediated dilatation (FMD) is a surrogate marker validated for evaluating endothelial dysfunction. Our objective was to identify risk factors associated to endothelial dysfunction in children with chronic kidney disease. Materials and methods: Children 2-16 years of age were studied. Clinical information and biochemical variables were gathered, including intact parathyroid hormone (iPTH), interleukins 6 and 1, high sensitivity C reactive protein (hsCRP), reduced glutathione, nitric oxide, malondialdehyde and homocysteine. FMD was measured, and considered altered if < 7%. Results: Included were 129 patients aged 13.1 ± 2.6 years. FMD < 7% was found in 69 (52.7%). Patients with altered FMD had higher levels of triglycerides and hsCRP than those with normal FMD (145.5 vs. 120.0 mg/dL, P = .042, and 1.24 vs. 0.55 U/L, P = .007, respectively), as well as higher frequency of low iPTH (19.1 vs. 4.9%, P = .036). Levels of hsCRP correlated significantly with FMD (Rho = −0.28, P = .003). Patients with low iPTH (OR 4.41, 95% CI 1.13- 17.27, P = .033) and increased hsCRP (OR 2.89, 95% CI 1.16-7.17, P = .022) had higher adjusted risk of having FMD < 7%. Conclusions: Hypertriglyceridemia, inflammation and low iPTH associated significantly with altered FMD. They are frequent, treatable risk factors for cardiovascular disease.