We aimed to evaluate the effectiveness and safety of single-course initial regimens in patients with low-risk gestational trophoblastic neoplasia (GTN). In this trial (NCT01823315), 276 patients were analyzed. Patients were allocated to three initiated regimens: single-course methotrexate (MTX), single-course MTX+ dactinomycin (ACTD), and multi-course MTX (control arm). The primary endpoint was the complete remission (CR) rate by initial drug(s). The primary CR rate was 64.4% with multi-course MTX in the control arm. For the single-course MTX arm, the CR rate was 35.8% by one course; it increased to 59.3% after subsequent multi-course MTX, with non-inferiority to the control (difference –5.1%, 95% confidence interval (CI) –19.4% to 9.2%, P=0.014). After further treatment with multi-course ACTD, the CR rate (93.3%) was similar to that of the control (95.2%, P=0.577). For the single-course MTX+ACTD arm, the CR rate was 46.7% by one course, which increased to 89.1% after subsequent multi-course, with non-inferiority (difference 24.7%, 95% CI 12.8%–36.6%, P<0.001) to the control. It was similar to the CR rate by MTX and further ACTD in the control arm (89.1% vs. 95.2%, P=0.135). Four patients experienced recurrence, with no death, during the 2-year follow-up. We demonstrated that chemotherapy initiation with single-course MTX may be an alternative regimen for patients with low-risk GTN.