Abstract Background and Aims Continuous renal replacement therapy (CRRT) and sustained low-efficiency dialysis (SLED) are usually used for critically ill patients with acute kidney injury when indicated. Most studies done throughout the years showed no statistically significant difference in outcomes between the two modalities. Thus, this study aims to determine the outcomes and associated factors of both CRRT and SLED in patients with AKI. Hence, this will allow us to determine our competency as an institution in using CRRT and SLED to formulate recommendations and protocols in the future. Method We conducted a retrospective cohort study of patients who developed acute kidney injury and underwent either SLED or CRRT in the ICU of a tertiary hospital in Makati City, Metro Manila. Patients who are on maintenance hemodialysis, who underwent both sustained low-efficiency dialysis and continuous replacement therapy, and who did not complete or tolerate 1 session of SLED or 24 hours of CRRT were excluded in the study. Key outcomes investigated were all-cause mortality at 30 days and dialysis dependence at 30 days after initiation of treatment. Results Eighty-four patients who were initiated with either SLED (N=48) or CRRT (N=36). There was a significant difference in terms of all-cause mortality between modalities 20 (42%) for SLED and 33 (92%) for CRRT, p-value=0.000). Among variables used in the study, higher vasopressor requirement (aOR 2.78, 95% CI: 1.47-5.25, p=0.002) and age (aOR 2.21, 95% CI: 1.13-4.33, p=0.021) at initiation were associated with higher likelihood of mortality across modalities. Thirteen patients (28%) who underwent SLED were dependent on dialysis at 30 days. Baseline serum creatinine (aOR 3.21 95% CI: 1.17-8.79, p=0.023) and serum creatinine at initiation (aOR 4.11, 95% CI: 1.43-22.56, p=0.014) were identified to be associated with dialysis dependence. Sub-analysis of the CRRT group showed continuous veno-venous hemodialysis (CVVHD) (aOR 16.57, 95% CI: 3.54-77.49, p<0.001) was associated with higher likelihood of mortality among CRRT modalities. Conclusion Increased mortality was seen in patients who underwent CRRT especially CVVHD and was associated with age and number of vasopressors present during initiation of renal replacement therapy.