Background. During 2014–2015, an outbreak of Ebola virus disease (EVD) swept across parts of West Africa. No approved antiviral drugs are available for Ebola treatment currently. Methods. A retrospective clinical case series was performed for EVD patients in Sierra Leone–China Friendship Hospital. Patients with confirmed EVD were sequentially enrolled and treated with either World Health Organization (WHO)–recommended supportive therapy (control group) from 10 to 30 October, or treated with WHO-recommended therapy plus favipiravir (T-705) from 1 to 10 November 2014. Survival and virological characteristics were observed for 85 patients in the control group and 39 in the T-705 treatment group. Results. The overall survival rate in the T-705 treatment group was higher than that of the control group (56.4% 22/39 vs 35.3% 30/85; P = .027). Among the 35 patients who finished all designed endpoint observations, the survival rate in the T-705 treatment group (64.8% 11/17) was higher than that of the control group (27.8% 5/18). Furthermore, the average survival time of the treatment group (46.9 ± 5.6 days) was longer than that of the control group (28.9 ± 4.7 days). Most symptoms of patients in the treatment group improved significantly. Additionally, 52.9% of patients who received T-705 had a >100-fold viral load reduction, compared with only 16.7% of patients in the control group. Conclusions. Treatment of EVD with T-705 was associated with prolonged survival and markedly reduced viral load, which makes a compelling case for further randomized controlled trials of T-705 for treating EVD.