OBJECTIVE: We explored the risk factors for the occurrence of delayed facial paralysis (DFP) after microvascular decompression (MVD) for hemifacial spasm (HFS). METHODS: A retrospective study was conducted of 636 patients who had undergone MVD for HFS by the same neurosurgery department of China-Japan Friendship Hospital from January 2006 to May 2016. Of the 636 patients, 50 (7.9%) had presented with DFP, which had developed from 2 to 60 days postoperatively (average, 12.9 +/- 10.0005 days). All 50 patients with DFP had recovered completely within 10-300 days (average, 88.7 +/- 61.389 days) after the onset of DFP. We randomly selected 100 patients from the 586 patients without DFP as the control group. Univariate and multivariate logistic analyses were used to analyze the risk factors involved in the occurrence of DFP. RESULTS: Univariate analysis showed that the disease course was the only factor associated with the development of DFP (P = 0.003). Furthermore, on multivariate logistic analysis, the course of HFS was the only risk factor associated with the development of DFP (P = 0.01). Additionally, the Spearman test revealed a positive correlation between the onset of DFP and the duration of the DFP symptoms (r(s) = 0.682; P < 0.001). CONCLUSION: Although DFP frequently occurred after MVD, it can recover spontaneously. The longer the course of HFS, the more frequently DFP will occur after MUD. The earlier that DFP develops, the shorter will be the time to recovery.