Background: Urine volume less than 1 mL/kg/h is called oliguria. The treatment of these patients is very important. Objectives: This study aimed to compare dopamine and drip Lasix in children with oliguria. Methods: This study was performed as a clinical trial in the NICU, PICU, neonatal and pediatric wards of Amirkabir hospital in Arak. Children with oliguria with less than 1 mL/kg/h during treatment were considered the study group. Sixty children who met the inclusion criteria were selected and randomly divided into two groups, including 30 children in the dopamine group and 30 children in the Lasix group. In the dopamine group, the drug was administered at a dose of 3 µg/kg/min, in the second group, drip Lasix was administered at a dose of 0.05 mg/kg/h. Results: In this evaluation, after evaluating the patients in both groups, it was observed that mean ± SD of age was 2.76 ± 1.85 years, and 51.7% of children have female gender (P = 0.438). The mean ± SD of creatinine in children after receiving dopamine and drip Lasix was 0.87 ± 0.2 mg/dl (P = 0.0001) and 0.84 ± 0.17 mg/dl (P = 0.000), respectively. Conclusions: Both drip Lasix and dopamine improved the condition of patients with oliguria. In addition, there was no statistically significant difference between these two drugs, so both drugs could improve the condition of patients.