Objective <p>Postterm choriocarcinoma is rare and seldom reported. Patients with postterm choriocarcinoma have unfavorable outcomes. Thus, we conducted a retrospective study to better understand this disease.</p> Methods <p>Thirty-five patients with postterm choriocarcinoma who received treatment at West China Second University Hospital from January 2011 to August 2022 were enrolled.</p> Results <p>The most common symptom in our cohort was abnormal uterine bleeding (25/35, 71.4%). Interval to diagnosis, serum β-hCG, and FIGO score or FIGO stage were not related to recurrence (<i>P</i> = 0.523, <i>P</i> = 0.812, <i>P</i> = 0.343, <i>P</i> = 0.440). However, the number of chemotherapy courses before achieving normal β-hCG (crude hazard ratio [HR] [95% confidence interval [CI]: 1.15 [1.04–1.26], <i>P</i> = 0.007) was positively related to recurrence, while the number of consolidation chemotherapy courses was negatively related to recurrence (crude HR [95% CI]: 0.51 [0.30–0.88], <i>P</i> = 0.015). Patients who received EMA-CO had a lower risk of recurrence, but the difference was not statistically significant (crude HR [95% CI]: 0.41 [0.08–2.06], <i>P</i> = 0.281). Patients who received other regimens (other than EMA-CO or 5-FU + Act-D) had a significantly higher risk of recurrence (crude HR [95% CI]: 8.30 [1.61–42.78], <i>P</i> = 0.011).</p> Conclusions <p>The complete remission rate of postterm choriocarcinoma was 88.6% in our study. Serum β-hCG surveillance and/or pathological examination of curettage might lead to an earlier diagnosis. The number of consolidation chemotherapy courses was negatively related to recurrence.</p> Clinical trial number <p>Not applicable.</p>