Abstract Background and Aims The new coronavirus disease (COVID-19) pandemic faced the healthcare sector worldwide with an unprecedented challenge. Although respiratory failure is the main feature of the disease, renal involvement is also common, particularly in critically ill patients, and often requires urgent dialysis treatment. This study aimed to analyse clinical features and risk factors for poor outcomes in patients with COVID-19-associated acute kidney injury (AKI) requiring dialysis. Method All 98 patients included in this retrospective observational study were treated in the first hospital in Serbia transformed to exclusively admit COVID-19 patients at the onset of the epidemic. Data were collected from clinical charts and patient histories for the period between March 19, 2020, and March 19, 2022, and analysed with SPSS software, version 22 (IBM Corporation, New York, USA). Results Out of 6,540 non-pregnant adult patients hospitalized for COVID-19 (1,955 in the intensive care unit) in the observed period, 98 (85.7% male, age range 25-89 years) developed dialysis-requiring AKI. A total of 312 hemodialyses (HD) treatments were performed (3.18±2.39, range 1-12, per patient), mostly intermittent HD (85.7% of patients) pertaining to technical resources. The majority of patients (90.8%) had at least one comorbidity – hypertension (38.8%), diabetes (28.6%), cardiovascular disease (11.2%), cerebrovascular disease (3.1%), chronic respiratory disease (7.1%), malignancy (6.1%), or autoimmune disease (1.0%). Most patients (90.8%) required mechanical ventilation. Only 8 (8.2%) were vaccinated. Nearly half (49.0%) of the patients had bilateral pneumonia and 2.0% had ARDS at presentation, with an average CT severity score of 14.05±6.72 (range 1-25) at presentation. Time to AKI presentation was 8.96±5.14 days (range 2-25). The overall mortality rate was 91.8%. Surviving patients had significantly more HD procedures performed (5.00±2.39 vs 3.02±2.34; P = .024) and significantly lower procalcitonin level (1.89±0.16 ng/mL vs 6.14±9.57 ng/mL; P = .015) at presentation. Fatal outcome was significantly more common in individuals requiring mechanical ventilation (p<0.001). Other demographic (age, sex, smoking habit), clinical (comorbidities, vaccination status, radiographic finding, CT severity score, time to AKI onset, type of dialysis) and laboratory parameters (WBC, neutrophil/lymphocyte ratio, CK, LDH, urea, creatinine, CRP, IL-6, D-dimer, ferritin) were not significantly associated with adverse outcome. Multiple logistic regression showed that fewer HD procedures were significantly associated with a higher mortality rate (OR 0.77, 95% CI 0.60-0.99, P = .039). Conclusion Patients who develop dialysis-requiring AKI in the setting of COVID-19 have an extremely high mortality rate. Higher procalcitonin, the need for mechanical ventilation and a lower number of HD procedures are significantly associated with fatal outcomes in this population.