Objective To introduce the operative technique of cyst neck sealing with free-fat graft for sacral Tarlov cyst and to observe its clinical therapeutic effect. Methods This retrospective study included 59 cases of symptomatic sacral Tarlov cysts treated by cyst neck sealing with free-fat graft from January 2010 to February 2016 at Neurosurgical Department of Army General Hospital of PLA (42 cases), Tsinghua University Yuquan Hospital (14 cases) and Fengning Hospital of Hebei Province (3 cases). The key points of operation were cutting cystic wall, identifying the nerve root and opening of cyst neck within cyst, cutting the cyst neck open and suturing the wound with free-fat graft in it to reconstruct root sheath in order to avoid cerebrospinal fluid leakage and root compression. The pain severity was assessed according to visual analog scale (VAS). Results The VAS score was 7.5±1.8 before operation and decreased to 2.7±0.6 and 2.3±0.5 at 6 and 18 months post operation, respectively. The difference was statistically significant (P=0.008). There was no complication relevant to operation. During the 10-18 (average: 15.0±3.7) months after operation, MRI follow-up was conducted. The latest MRI results showed complete obliteration of cysts in 54 cases and a little hydrops ex vacuo in lower place of original cyst cavity in 5 cases without cyst and symptom relapses. Conclusion Cyst neck sealing with free-fat graft for treatment of sacral Tarlov cysts is safe and may have better long-term effects. Key words: Tarlov cysts; Microsurgery; Sacral; Fat