Background & aims. Frailty syndrome, characterized by loss of functional reserves and vulnerability to acute stressors, conditionate a higher risk of adverse outcomes and mortality. Its prevalence is mainly high (65%) in patients with End Stage Kidney Disease, receiving renal replacement therapy. Methods. Cross-sectional study with a non-probabilistic sampling of adult patients with chronic kidney disease stage 5 that initiated renal replacement therapy at a dialysis centre from Santander, Colombia. The main objective was to estimate the prevalence of frailty syndrome and to describe the clinical and functional characteristics of the studied population. The frailty syndrome was defined through the FRAIL Questionnaire. Results. Sixty-six subjects were included. The median age was 65 years (IQR 58-69). 54.55% were frail. The median age in frail patients was higher than the one in non-frail (p = 0.019). The prevalence of frailty syndrome was higher in women than in men (p = 0.045). Frail patients had a higher Charlson comorbidity index (p =< 0.01). The mean serum creatinine, parathyroid hormone (PTH), and albumin were lower in frail patients, with statistically significant differences. Conclusions. The prevalence of frailty in patients that initiate renal replacement therapy in Santander, Colombia, is similar to that reported in other latitudes. Although the FRAIL Scale is based on the self-report, it counts with studies that endorse its reproductivity. Albumin and creatinine serum levels are decreased in subjects with frailty syndrome, behaving as frailty biomarkers in our research.