Objectives: To estimate early mortality in patients with chronic kidney disease who started emergency haemodialysis between 2012 and 2014 in a national referral hospital in Lima, Peru, and to identify risk factors. Design, characteristics, participants and measurements: A retrospective cohort study was conducted by reviewing the medical records of all patients admitted to the hospital's Haemodialysis Unit from 2012 to 2014. Early mortality, defined as death within the first 90 days of starting haemodialysis, as well as age, gender, chronic kidney disease aetiology, comorbidities, cause of death, estimated glomerular filtration rate, vascular access and other variables were evaluated in patients who initiated emergency haemodialysis. Early mortality was estimated using frequencies, and risk factors were determined by Poisson regression with robust variance. Results: 43.4% of patients were female, 51.5% were aged ≥65 years and the early mortality rate was 9.3%. The main risk factors were estimated glomerular filtration rate >10 mL/min/1.73 m2 (RR: 2.72 [95% CI: 1.60–4.61]); age ≥65 years (RR: 2.51 [95% CI: 1.41–4.48]); central venous catheter infection, RR: 2.25 (95% CI: 1.08–4.67); female gender, RR: 2.15 (95% CI: 1.29–3.58); and albumin < 3.5 g/dL (RR: 1.97 [95% CI: 1.01–3.82]). Conclusions: Early mortality was 9.3%. The main risk factor was starting haemodialysis with an estimated glomerular filtration rate >10 mL/min/1.73 m2.