The study was designed to investigate the effect of cerebrospinal fluid leakage (CFSL) on the surgical outcomes of thoracic spinal stenosis (TSS). 153 TSS cases were recruited for this study from January 2012 to December 2017. Preoperative duration of symptoms, neurological status, operative parameters, postoperative courses and neurological recovery were collected. Modified Japanese Orthopedic Association (JOA) score for thoracic myelopathy was used to assess neurological status, and recovery rate was calculated, accordingly. Comparison was between postoperative transient neurological deterioration (PTND) group and Non-PTND group. Cases were further grouped into favorable outcome (FO) (JOA recovery rate ≥25%) and unfavorable outcome (UO) (JOA recovery rate <25%) group, respectively. Further, multivariate logistic regression was performed to verify their relationships. Result showed that seventeen patients (11.1%) developed PTND, while sixty-seven patients (43.8%) developed CSFL. The mean JOA recovery rate was 58.2 ± 35.3%. The incidence of CSFL in PTND group was significantly lower than that in non-PTND group (17.65% vs 47.06%, p = 0.02). Multiple regression analysis showed that CSFL indicated a lower incidence of PTND (B = 1.608, p = 0.03). However, there was no significant difference between the incidence of CSFL in FO group and that of UO group (27.28% vs 46.56%, p = 0.09). In addition, preoperative duration of symptoms, preoperative JOA score and blood loss were associated with the surgical outcomes. The present study found that CSFL was associated with a lower risk of PTND in TSS, which has a certain guiding significance for clinical surgery.